| DOTS | M. Chen |
| Internet-Draft | Li. Su |
| Intended status: Informational | Jin. Peng |
| Expires: January 7, 2020 | CMCC |
| July 06, 2019 |
A method for dots server deployment
draft-chen-dots-server-hierarchical-deployment-00
As DOTS is used for DDoS Mitigation signaling, In practice, there are different deployment scenarios for DOTS agents deployment depending on the network deployment mode. This document made an accommandation for DOTS Server deployment which may be Suitable for ISP. The goal is to provide some guidance for DOTS agents deployment.
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DDoS Open Threat Signaling (DOTS) is a protocol to standardize real-time signaling, threat-handling requests[I-D.ietf-dots-signal-channel], when attack target is under attack, dots client send mitigation request to dots server for help, If the mitigation request contains enough messages of the attack, then the mitigator can respond very effectively.
In the architecture draft[I-D.ietf-dots-architecture], it is says that this does not necessarily imply that the attack target and the DOTS client have to be co-located in the same administrative domain, but it is expected to be a common scenario. Although co-location of DOTS server and mitigator within the same domain is expected to be a common deployment model, it is assumed that operators may require alternative models.
In the DOTS server discovery draft[I-D.ietf-dots-server-discovery], it is says that a key point in the deployment of DOTS is the ability of network operators to be able to onfigure DOTS clients with the correct DOTS server(s) nformation consistently.
In the DOTS multihoming draft[I-D.ietf-dots-multihoming], it provides deployment recommendations for DOTS client and DOTS gateway, it is says when conveying a mitigation request to protect the attack target, the DOTS client among the DOTS servers available Must select a DOTS server whose network has assigned the prefixes from which target prefixes and target IP addresses are derived. This implies that id no appropriate DOTS server is found, the DOTS client must not send the mitigation request to any DOTS server. So in this document, we give some dots server deployment consideration as the title suggests we prefer hierarchical deployment.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]
The readers should be familiar with the terms defined in [I-D.ietf-dots-requirements] [I-D.ietf-dots-use-cases]
The terminology related to YANG data modules is defined in [RFC7950]
In addition, this document uses the terms defined below:
When take dots server deployment into consideration, one thing must be involved is mitigator.so far, how many network devices can play the role of mitigator, we make a summerized list as follows:
Whether DOTS server can be deployed, the following conditions need to be met:
From the internal structure of ISP, the whole network can divide into three parts logically. There are three most important routers: backbone router, man(metropolitan area network) router, and IDC router. When a ddos attack occurs, it must be one of the three cases as follows, and the corresponding mitigator will responsible for mitigation.
+---------+
|other ISP|
+---------+
.........|..........................
| backbone network
+---------------+ +----------+
|backbone router|-----|mitigator1|
+---------------+ +----------+
|dots svr1|
+---------+
..........|.................................
| metropolitan area network
+----------+ +----------+
|man router|-------|mitigator2|
+----------+ +----------+
|dots svr2|
+---------+
..........|.........................
| local area network
+----------+ +----------+
|IDC router|------|mitigator3|
+----------+ +----------+
|dots svr3|
+---------+
|
|
+-----------+ +-------------+
|dots client|-------|attack target|
+-----------+ +-------------+
Figure 1: DOTS Server Deployment
The coexistence of different operators is very common, coordination between operators across networks is very important. Interdomain attacks occur frequently, We recommend deploying the DOTS server at the access point
+-------------+ +-------------+
| ISP A |--------| ISP B |
| +---------+ | | +---------+ |
| |dots svrA| | | |dots svrB| |
+-------------+ +-------------+
| |
+-------------+-------------+
|
+-------------+
| ISP C |
| +---------+ |
| |dots svrC| |
+-------------+
Figure 2: DOTS Server Deployment2
TBD
TBD
TBD
| [RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997. |
| [RFC7950] | Bjorklund, M., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016. |