Internet DRAFT - draft-psarkar-rtgwg-multihomed-prefix-lfa
draft-psarkar-rtgwg-multihomed-prefix-lfa
Routing Area Working Group P. Sarkar, Ed.
Internet-Draft S. Hegde
Intended status: Informational C. Bowers
Expires: July 22, 2016 Juniper Networks, Inc.
U. Chunduri, Ed.
J. Tantsura
Ericsson Inc.
B. Decraene
Orange
H. Gredler
Unaffiliated
January 19, 2016
LFA selection for Multi-Homed Prefixes
draft-psarkar-rtgwg-multihomed-prefix-lfa-03
Abstract
This document shares experience gained from implementing algorithms
to determine Loop-Free Alternates for multi-homed prefixes. In
particular, this document provides explicit inequalities that can be
used to evaluate neighbors as a potential alternates for multi-homed
prefixes. It also provides detailed criteria for evaluating
potential alternates for external prefixes advertised by OSPF ASBRs.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC2119 [RFC2119].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on July 22, 2016.
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Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Acronyms . . . . . . . . . . . . . . . . . . . . . . . . 3
2. LFA inequalities for MHPs . . . . . . . . . . . . . . . . . . 4
3. LFA selection for the multi-homed prefixes . . . . . . . . . 4
3.1. Improved coverage with simplified approach to MHPs . . . 6
3.2. IS-IS ATT Bit considerations . . . . . . . . . . . . . . 7
4. LFA selection for the multi-homed external prefixes . . . . . 8
4.1. IS-IS . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.2. OSPF . . . . . . . . . . . . . . . . . . . . . . . . . . 8
4.2.1. Rules to select alternate ASBR . . . . . . . . . . . 8
4.2.2. Multiple ASBRs belonging different area . . . . . . . 9
4.2.3. Type 1 and Type 2 costs . . . . . . . . . . . . . . . 10
4.2.4. RFC1583compatibility is set to enabled . . . . . . . 10
4.2.5. Type 7 routes . . . . . . . . . . . . . . . . . . . . 10
4.2.6. Inequalities to be applied for alternate ASBR
selection . . . . . . . . . . . . . . . . . . . . . . 10
4.2.6.1. Forwarding address set to non zero value . . . . 10
4.2.6.2. ASBRs advertising type1 and type2 cost . . . . . 11
5. LFA Extended Procedures . . . . . . . . . . . . . . . . . . . 12
5.1. Links with IGP MAX_METRIC . . . . . . . . . . . . . . . . 12
5.2. Multi Topology Considerations . . . . . . . . . . . . . . 13
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
8. Security Considerations . . . . . . . . . . . . . . . . . . . 14
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
9.1. Normative References . . . . . . . . . . . . . . . . . . 14
9.2. Informative References . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
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1. Introduction
The use of Loop-Free Alternates (LFA) for IP Fast Reroute is
specified in [RFC5286]. Section 6.1 of [RFC5286] describes a method
to determine loop-free alternates for a multi-homed prefixes (MHPs).
This document describes a procedure using explicit inequalities that
can be used by a computing router to evaluate a neighbor as a
potential alternate for a multi-homed prefix. The results obtained
are equivalent to those obtained using the method described in
Section 6.1 of [RFC5286]. However, some may find this formulation
useful.
Section 6.3 of [RFC5286] discusses complications associated with
computing LFAs for multi-homed prefixes in OSPF. This document
provides detailed criteria for evaluating potential alternates for
external prefixes advertised by OSPF ASBRs, as well as explicit
inequalities.
This document also provide clarifications, additional considerations
to [RFC5286], to address a few coverage and operational observations.
These observations are in the area of handling IS-IS attach (ATT) bit
in Level-1 (L1) area, links provisioned with MAX_METRIC for traffic
engineering (TE) purposes and in the area of Multi Topology (MT) IGP
deployments. All these are elaborated in detail in Section 3.2 and
Section 5.
1.1. Acronyms
AF - Address Family
ATT - IS-IS Attach Bit
ECMP - Equal Cost Multi Path
IGP - Interior Gateway Protocol
IS-IS - Intermediate System to Intermediate System
OSPF - Open Shortest Path First
MHP - Multi-homed Prefix
MT - Multi Topology
SPF - Shortest Path First PDU
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2. LFA inequalities for MHPs
This document proposes the following set of LFA inequalities for
selecting the most appropriate LFAs for multi-homed prefixes (MHPs).
They can be derived from the inequalities in [RFC5286] combined with
the observation that D_opt(N,P) = Min (D_opt(N,PO_i) + cost(PO_i,P))
over all PO_i
Link-Protection:
D_opt(N,PO_i)+ cost(PO_i,P) < D_opt(N,S) +
D_opt(S,PO_best) + cost(PO_best,P)
Link-Protection + Downstream-paths-only:
D_opt(N,PO_i)+ cost(PO_i,P) < D_opt(S,PO_best) + cost(PO_best,P)
Node-Protection:
D_opt(N,PO_i)+ cost(PO_i,P) < D_opt(N,E) +
D_opt(E,PO_best) + cost(PO_best,P)
Where,
S - The computing router
N - The alternate router being evaluated
E - The primary next-hop on shortest path from S to
prefix P.
PO_i - The specific prefix-originating router being
evaluated.
PO_best - The prefix-originating router on the shortest path
from the computing router S to prefix P.
Cost (X,P) - Cost of reaching the prefix P from prefix
originating node X.
D_opt(X,Y) - Distance on the shortest path from node X to node
Y.
Figure 1: LFA inequalities for MHPs
3. LFA selection for the multi-homed prefixes
To compute a valid LFA for a given multi-homed prefix P, through an
alternate neighbor N a computing router S MUST follow one of the
appropriate procedures below.
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Link-Protection :
=================
1. If alternate neighbor N is also prefix-originator of P,
1.a. Select N as a LFA for prefix P (irrespective of
the metric advertised by N for the prefix P).
2. Else, evaluate the link-protecting LFA inequality for P with
the N as the alternate neighbor.
2.a. If LFA inequality condition is met,
select N as a LFA for prefix P.
2.b. Else, N is not a LFA for prefix P.
Link-Protection + Downstream-paths-only :
=========================================
1. Evaluate the link-protecting + downstream-only LFA inequality
for P with the N as the alternate neighbor.
1.a. If LFA inequality condition is met,
select N as a LFA for prefix P.
1.b. Else, N is not a LFA for prefix P.
Node-Protection :
=================
1. If alternate neighbor N is also prefix-originator of P,
1.a. Select N as a LFA for prefix P (irrespective of
the metric advertised by N for the prefix P).
2. Else, evaluate the apporpriate node-protecting LFA inequality
for P with the N as the alternate neighbor.
2.a. If LFA inequality condition is met,
select N as a LFA for prefix P.
2.b. Else, N is not a LFA for prefix P.
Figure 2: Rules for selecting LFA for MHPs
In case an alternate neighbor N is also one of the prefix-originators
of prefix P, N MAY be selected as a valid LFA for P.
However if N is not a prefix-originator of P, the computing router
SHOULD evaluate one of the corresponding LFA inequalities, as
mentioned in Figure 1, once for each remote node that originated the
prefix. In case the inequality is satisfied by the neighbor N router
S MUST choose neighbor N, as one of the valid LFAs for the prefix P.
When computing a downstream-only LFA, in addition to being a prefix-
originator of P, router N MUST also satisfy the downstream-only LFA
inequality specified in Figure 1.
For more specific rules please refer to the later sections of this
document.
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3.1. Improved coverage with simplified approach to MHPs
LFA base specification [RFC5286] Section 6.1 recommends that a router
compute the alternate next-hop for an IGP multi-homed prefix by
considering alternate paths via all routers that have announced that
prefix and the same has been elaborated with appropriate inequalities
in the above section. However, [RFC5286] Section 6.1 also allows for
the router to simplify the multi-homed prefix calculation by assuming
that the MHP is solely attached to the router that was its pre-
failure optimal point of attachment, at the expense of potentially
lower coverage. If an implementation chooses to simplify the multi-
homed prefix calculation by assuming that the MHP is solely attached
to the router that was its pre-failure optimal point of attachment,
the procedure described in this memo can potentially improve coverage
for equal cost multi path (ECMP) MHPs without incurring extra
computational cost.
While the approach as specified in [RFC5286] Section 6.1 last
paragraph, is to simplify the MHP as solely attached to the router
that was its pre-failure optimal point of attachment; though it is a
scalable approach and simplifies computation, [RFC5286] notes this
may result in little less coverage.
This memo improves the above approach to provide loop-free
alternatives without any additional cost for equal cost multi path
MHPs as described through the below example network. The approach
specified here MAY also be applicable for handling default routes as
explained in Section 3.2.
5 +---+ 8 +---+ 5 +---+
+-----| S |------| A |-----| B |
| +---+ +---+ +---+
| | |
| 5 | 5 |
| | |
+---+ 5 +---+ 4 +---+ 1 +---+
| C |---| E |-----| M |-------| F |
+---+ +---+ +---+ +---+
| 10 5 |
+-----------p---------+
Figure 3: MHP with same ECMP Next-hop
In the above network a prefix p, is advertised from both Node E and
Node F. With simplified approach taken as specified in [RFC5286]
Section 6.1, prefix p will get only link protection LFA through the
neighbor C while a node protection path is available through neighbor
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A. In this scenario, E and F both are pre-failure optimal points of
attachment and share the same primary next-hop. Hence, an
implementation MAY compare the kind of protection A provides to F
(link-and-node protection) with the kind of protection C provides to
E (link protection) and inherit the better alternative to prefix p
and here it is A.
However, in the below network prefix p has an ECMP through both node
E and node F with cost 20. Though it has 2 pre-failure optimal
points of attachment, the primary next-hop to each pre-failure
optimal point of attachment is different. In this case, prefix p
shall inherit corresponding LFA to each primary next-hop calculated
for the router advertising the same respectively (node E's and node
F's LFA).
+---+ 3 +---+
| S |----------------| B |
+---+ +---+
| |
10 | 1 |
| |
+---+ 6 +---+
| E |-----------------| F |
+---+ +---+
| 10 16 |
+-----------p---------+
Figure 4: MHP with different ECMP Next-hops
In summary, if there are multiple pre-failure points of attachment
for a MHP and primary next-hop of a MHP is same as that of the
primary next-hop of the router that was pre-failure optimal point of
attachment, an implementation MAY provide the better protection to
MHP without incurring any additional computation cost.
3.2. IS-IS ATT Bit considerations
Per [RFC1195] a default route needs to be added in Level1 (L1) router
to the closest reachable Level1/Level2 (L1/L2) router in the network
advertising ATT (attach) bit in its LSP-0 fragment. All L1 routers
in the area would do this during the decision process with the next-
hop of the default route set to the adjacent router through which the
closest L1/L2 router is reachable. The base LFA specification
[RFC5286] does not specify any procedure for computing LFA for a
default route in IS-IS L1 area. Potentially one MAY consider a
default route is being advertised from the border L1/L2 router where
ATT bit is set and can do LFA computation for the default route.
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But, when multiple ECMP L1/L2 routers are reachable in an L1 area
corresponding best LFAs SHOULD be given for each primary next-hop
associated with default route. Considerations as specified in
Section 3 and Section 3.1 are applicable for default routes, if the
default route is considered as ECMP MHP.
4. LFA selection for the multi-homed external prefixes
Redistribution of external routes into IGP is required in case of two
different networks getting merged into one or during protocol
migrations. External routes could be distributed into an IGP domain
via multiple nodes to avoid a single point of failure.
During LFA calculation, alternate LFA next-hops to reach the best
ASBR could be used as LFA for the routes redistributed via that ASBR.
When there is no LFA available to the best ASBR, it may be desirable
to consider the other ASBRs (referred to as alternate ASBR hereafter)
redistributing the external routes for LFA selection as defined in
[RFC5286] and leverage the advantage of having multiple re-
distributing nodes in the network.
4.1. IS-IS
LFA evaluation for multi-homed external prefixes in IS-IS is similar
to the multi-homed internal prefixes. Inequalities described in sec
2 would also apply to multi-homed external prefixes as well.
4.2. OSPF
Loop free Alternates [RFC 5286] describes mechanisms to apply
inequalities to find the loop free alternate neighbor. For the
selection of alternate ASBR for LFA consideration, additional rules
have to be applied in selecting the alternate ASBR due to the
external route calculation rules imposed by [RFC 2328].
This document also defines the inequalities defined in RFC [5286]
specifically for the alternate loop-free ASBR evaluation.
4.2.1. Rules to select alternate ASBR
The process to select an alternate ASBR is best explained using the
rules below. The below process is applied when primary ASBR for the
concerned prefix is chosen and there is an alternate ASBR originating
same prefix.
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1. If RFC1583Compatibility is disabled
1a. if primary ASBR and alternate ASBR are intra area
non-backbone path go to step 2.
1b. If primary ASBR and alternate ASBR belong to
intra-area backbone and/or inter-area path go
to step 2.
1c. for other paths, skip the alternate ASBR and
consider next ASBR.
2. If cost type (type1/type2) advertised by alternate
ASBR same as primary
2a. If not same skip alternate ASBR and consider next ASBR.
3. If cost type is type1
3a. If cost is same, program ECMP
3b. else go to step 5.
4 If cost type is type 2
4a. If cost is different, skip alternate ASBR and
consider next ASBR
4b. If type2 cost is same, compare type 1 cost.
4c. If type1 cost is also same program ECMP.
4d. If type 1 cost is different go to step 5.
5. If route type (type 5/type 7)
5a. If route type is same, check route p-bit,
forwarding address field for routes from both
ASBRs
match. If not skip alternate ASBR and consider
next ASBR.
5b. If route type is not same, skip ASBR
and consider next ASBR.
6. Apply inequality on the alternate ASBR.
Figure 5: Rules for selecting alternate ASBR in OSPF
4.2.2. Multiple ASBRs belonging different area
When "RFC1583compatibility" is set to disabled, OSPF[RFC2328] defines
certain rules of preference to choose the ASBRs. While selecting
alternate ASBR for loop evaluation for LFA, these rules should be
applied and ensured that the alternate neighbor does not loop the
traffic back.
When there are multiple ASBRs belonging to different area advertising
the same prefix, pruning rules as defined in RFC 2328 section 16.4.1
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are applied. The alternate ASBRs pruned using above rules are not
considered for LFA evaluation.
4.2.3. Type 1 and Type 2 costs
If there are multiple ASBRs not pruned via rules defined in 3.2.2,
the cost type advertised by the ASBRs is compared. ASBRs advertising
Type1 costs are preferred and the type2 costs are pruned. If two
ASBRs advertise same type2 cost, the alternate ASBRs are considered
along with their type1 cost for evaluation. If the two ASBRs with
same type2 as well as type1 cost, ECMP FRR is programmed. If there
are two ASBRs with different type2 cost, the higher cost ASBR is
pruned. The inequalities for evaluating alternate ASBR for type 1
and type 2 costs are same, as the alternate ASBRs with different
type2 costs are pruned and the evaluation is based on equal type 2
cost ASBRS.
4.2.4. RFC1583compatibility is set to enabled
When RFC1583Compatibility is set to enabled, multiple ASBRs belonging
to different area advertising same prefix are chosen based on cost
and hence are valid alternate ASBRs for the LFA evaluation.
4.2.5. Type 7 routes
Type 5 routes always get preference over Type 7 and the alternate
ASBRs chosen for LFA calculation should belong to same type.Among
Type 7 routes, routes with p-bit and forwarding address set have
higher preference than routes without these attributes. Alternate
ASBRs selected for LFA comparison should have same p-bit and
forwarding address attributes.
4.2.6. Inequalities to be applied for alternate ASBR selection
The alternate ASBRs selected using above mechanism described in
3.2.1, are evaluated for Loop free criteria using below inequalities.
4.2.6.1. Forwarding address set to non zero value
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Link-Protection:
F_opt(N,PO_i)+ cost(PO_i,P) < D_opt(N,S) +
F_opt(S,PO_best) + cost(PO_best,P)
Link-Protection + Downstream-paths-only:
F_opt(N,PO_i)+ cost(PO_i,P) < F_opt(S,PO_best) + cost(PO_best,P)
Node-Protection:
F_opt(N,PO_i)+ cost(PO_i,P) < D_opt(N,E) +
F_opt(E,PO_best) + cost(PO_best,P)
Where,
S - The computing router
N - The alternate router being evaluated
E - The primary next-hop on shortest path from S to
prefix P.
PO_i - The specific prefix-originating router being
evaluated.
PO_best - The prefix-originating router on the shortest path
from the computing router S to prefix P.
cost(X,Y) - External cost for Y as advertised by X
F_opt(X,Y) - Distance on the shortest path from node X to Forwarding
address specified by ASBR Y.
D_opt(X,Y) - Distance on the shortest path from node X to node Y.
Figure 6: LFA inequality definition when forwarding address in non-
zero
4.2.6.2. ASBRs advertising type1 and type2 cost
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Link-Protection:
D_opt(N,PO_i)+ cost(PO_i,P) < D_opt(N,S) +
D_opt(S,PO_best) + cost(PO_best,P)
Link-Protection + Downstream-paths-only:
D_opt(N,PO_i)+ cost(PO_i,P) < D_opt(S,PO_best) + cost(PO_best,P)
Node-Protection:
D_opt(N,PO_i)+ cost(PO_i,P) < D_opt(N,E) +
D_opt(E,PO_best) + cost(PO_best,P)
Where,
S - The computing router
N - The alternate router being evaluated
E - The primary next-hop on shortest path from S to
prefix P.
PO_i - The specific prefix-originating router being
evaluated.
PO_best - The prefix-originating router on the shortest path
from the computing router S to prefix P.
cost(X,Y) - External cost for Y as advertised by X.
D_opt(X,Y) - Distance on the shortest path from node X to node Y.
Figure 7: LFA inequality definition for type1 and type 2 cost
5. LFA Extended Procedures
This section explains the additional considerations in various
aspects as listed below to the base LFA specification [RFC5286].
5.1. Links with IGP MAX_METRIC
Section 3.5 and 3.6 of [RFC5286] describes procedures for excluding
nodes and links from use in alternate paths based on the maximum link
metric (as defined in for IS-IS in [RFC5305] or as defined in
[RFC3137] for OSPF). If these procedures are strictly followed,
there are situations, as described below, where the only potential
alternate available which satisfies the basic loop-free condition
will not be considered as alternative.
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+---+ 10 +---+ 10 +---+
| S |------|N1 |-----|D1 |
+---+ +---+ +---+
| |
10 | 10 |
|MAX_MET(N2 to S) |
| |
| +---+ |
+-------|N2 |--------+
+---+
10 |
+---+
|D2 |
+---+
Figure 8: Link with IGP MAX_METRIC
In the simple example network, all the link costs have a cost of 10
in both directions, except for the link between S and N2. The S-N2
link has a cost of 10 in the direction from S to N2, and a cost of
MAX_METRIC in the direction from N2 to S (0xffffff /2^24 - 1 for IS-
IS and 0xffff for OSPF) for a specific end to end Traffic Engineering
(TE) requirement of the operator. At node S, D1 is reachable through
N1 with cost 20, and D2 is reachable through N2 with cost 20. Even
though neighbor N2 satisfies basic loop-free condition (inequality 1
of [RFC5286]) for D1 this could be excluded as potential alternative
because of the current exclusions as specified in section 3.5 and 3.6
procedure of [RFC5286]. But, as the primary traffic destined to D2
continue to use the link and hence irrespective of the reverse metric
in this case, the same link MAY be used as a potential LFA for D1.
Alternatively, reverse metric of the link MAY be configured with
MAX_METRIC-1, so that the link can be used as an alternative while
meeting the TE requirements.
5.2. Multi Topology Considerations
Section 6.2 and 6.3.2 of [RFC5286] state that multi-topology OSPF and
ISIS are out of scope for that specification. This memo clarifies
and describes the applicability.
In Multi Topology (MT) IGP deployments, for each MT ID, a separate
shortest path tree (SPT) is built with topology specific adjacencies,
the LFA principles laid out in [RFC5286] are actually applicable for
MT IS-IS [RFC5120] LFA SPF. The primary difference in this case is,
identifying the eligible-set of neighbors for each LFA computation
which is done per MT ID. The eligible-set for each MT ID is
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determined by the presence of IGP adjacency from Source to the
neighboring node on that MT-ID apart from the administrative
restrictions and other checks laid out in [RFC5286]. The same is
also applicable for OSPF [RFC4915] [MT-OSPF] or different AFs in
multi instance OSPFv3 [RFC5838].
However for MT IS-IS, if a default topology is used with MT-ID 0
[RFC5286] and both IPv4 [RFC5305] and IPv6 routes/AFs [RFC5308] are
present, then the condition of network congruency is applicable for
LFA computation as well. Network congruency here refers to, having
same address families provisioned on all the links and all the nodes
of the network with MT-ID 0. Here with single decision process both
IPv4 and IPv6 next-hops are computed for all the prefixes in the
network and similarly with one LFA computation from all eligible
neighbors per [RFC5286], all potential alternatives can be computed.
6. Acknowledgements
Thanks to Alia Atlas and Salih K A for their useful feedback and
inputs.
7. IANA Considerations
N/A. - No protocol changes are proposed in this document.
8. Security Considerations
This document does not introduce any change in any of the protocol
specifications and also this does not introduce any new security
issues other than as noted in the LFA base specification [RFC5286].
9. References
9.1. Normative References
[RFC1195] Callon, R., "Use of OSI IS-IS for routing in TCP/IP and
dual environments", RFC 1195, DOI 10.17487/RFC1195,
December 1990, <http://www.rfc-editor.org/info/rfc1195>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
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9.2. Informative References
[I-D.ietf-rtgwg-lfa-manageability]
Litkowski, S., Decraene, B., Filsfils, C., Raza, K.,
Horneffer, M., and P. Sarkar, "Operational management of
Loop Free Alternates", draft-ietf-rtgwg-lfa-
manageability-11 (work in progress), June 2015.
[RFC3137] Retana, A., Nguyen, L., White, R., Zinin, A., and D.
McPherson, "OSPF Stub Router Advertisement", RFC 3137,
DOI 10.17487/RFC3137, June 2001,
<http://www.rfc-editor.org/info/rfc3137>.
[RFC4915] Psenak, P., Mirtorabi, S., Roy, A., Nguyen, L., and P.
Pillay-Esnault, "Multi-Topology (MT) Routing in OSPF",
RFC 4915, DOI 10.17487/RFC4915, June 2007,
<http://www.rfc-editor.org/info/rfc4915>.
[RFC5120] Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
Topology (MT) Routing in Intermediate System to
Intermediate Systems (IS-ISs)", RFC 5120,
DOI 10.17487/RFC5120, February 2008,
<http://www.rfc-editor.org/info/rfc5120>.
[RFC5286] Atlas, A., Ed. and A. Zinin, Ed., "Basic Specification for
IP Fast Reroute: Loop-Free Alternates", RFC 5286,
DOI 10.17487/RFC5286, September 2008,
<http://www.rfc-editor.org/info/rfc5286>.
[RFC5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic
Engineering", RFC 5305, DOI 10.17487/RFC5305, October
2008, <http://www.rfc-editor.org/info/rfc5305>.
[RFC5308] Hopps, C., "Routing IPv6 with IS-IS", RFC 5308,
DOI 10.17487/RFC5308, October 2008,
<http://www.rfc-editor.org/info/rfc5308>.
[RFC5838] Lindem, A., Ed., Mirtorabi, S., Roy, A., Barnes, M., and
R. Aggarwal, "Support of Address Families in OSPFv3",
RFC 5838, DOI 10.17487/RFC5838, April 2010,
<http://www.rfc-editor.org/info/rfc5838>.
Authors' Addresses
Sarkar, et al. Expires July 22, 2016 [Page 15]
Internet-Draft LFA selection for Multi-Homed Prefixes January 2016
Pushpasis Sarkar (editor)
Juniper Networks, Inc.
Electra, Exora Business Park
Bangalore, KA 560103
India
Email: psarkar@juniper.net; pushpasis.ietf@gmail.com
Shraddha Hegde
Juniper Networks, Inc.
Electra, Exora Business Park
Bangalore, KA 560103
India
Email: shraddha@juniper.net
Chris Bowers
Juniper Networks, Inc.
1194 N. Mathilda Ave.
Sunnyvale, CA 94089
US
Email: cbowers@juniper.net
Uma Chunduri (editor)
Ericsson Inc.
300 Holger Way,
San Jose, California 95134
USA
Phone: 408 750-5678
Email: uma.chunduri@ericsson.com
Jeff Tantsura
Ericsson Inc.
300 Holger Way,
San Jose, California 95134
USA
Email: jeff.tantsura@ericsson.com
Sarkar, et al. Expires July 22, 2016 [Page 16]
Internet-Draft LFA selection for Multi-Homed Prefixes January 2016
Bruno Decraene
Orange
Email: bruno.decraene@orange.com
Hannes Gredler
Unaffiliated
Email: hannes@gredler.at
Sarkar, et al. Expires July 22, 2016 [Page 17]
