最近看到老东家发布了一篇很有意思的文章：Building an SRv6 uSID Data Center Fabric with SONiC，使用Sonic 构建基于SRv6 Fabric的DC架构。SRv6一般常用于骨干网和DCI，并且需要依托于BGP -> IGP迭代。其实之前在考虑城域网架构时，就思考过是否可以利用SRv6的高级特性，根据业务需求分割两个平面进行独立承载，但设备厂商提供的解决方案都是依托于IGP，而非Only BGP环境。最近阿里云在一些场合发布他们新的Peering架构ePF时提到过SRv6 only BGP，再结合这篇文章，没想到提前在Sonic Switch上先实现了，真的让人惊讶与开源社区的迭代速度。

这篇文章主要尝试下Sonic Switch，记录遇到的问题及解决方法。并测试SRv6实现到了什么程度，是否可以直接替代现有BGP Only的DC架构。PS：全部实验均是通过PNET搭建并验证，Sonic版本是从上面 那篇文章中下载的，基于202305版本，相关配置命令可以看那篇文章提到的github，以及FRR和Sonic的官方文档，为了方便，我列到了下面：

• https://github.com/segmentrouting/srv6-labs/tree/main/sonic-vs
• http://docs.frrouting.org/en/latest/zebra.html?highlight=json
• https://github.com/sonic-net/SONiC/blob/master/doc/srv6/srv6_hld.md

拓扑环境

      Ethernet0┌─────────┐Ethernet1
     ┌─────────┤   L2    ├──────────┐
     │         └─────────┘          │
     │Ethernet2                     │Ethernet2
┌────┴────┐                    ┌────┴────┐
│ POD1-L1 │                    │ POD2-L1 │
└────┬────┘                    └────┬────┘
     │Ethernet1                     │Ethernet1
     │                              │
     │Ethernet1                     │Ethernet1
┌────┴────┐                    ┌────┴────┐
│ POD1-L0 │                    │ POD2-L0 │
└────┬────┘                    └────┬────┘
     │Ethernet2                     │Ethernet2
     │                              │
     │eth2                          │eth0
 ┌───┴───┐                       ┌──┴────┐
 │  S1   │                       │  S2   │
 │ Server│                       │ Server│
 └───────┘                       └───────┘

注意：

在此篇文章里，简单总结下通过SRTE调度EVPN ELAN的流量，然后通过show信息，来查看引流及相关内容，并熟悉EVPN，EVPN基础部分，可以参考之前的文章，里面包含Route Type的信息：EVPN Summary

另外对于ELAN的引流，有很多种选择，常见的是通过对RT1打Color，调用单播流量；对RT3打Color，调用多播流量；对于RT1我们可以看成L3VPN中的“VRF”，也就是基于“VRF”颗粒度进行引流，这么理解可能更好理解

物理拓扑

In the article, only show as follow (because easy to show how to work):

Protocol: UDP; Port: 5234

Encoding: KV-GPB

For more detailed information, you can reference my colleague’s GitHub, which includes more examples, e.g GRPC.

AlexFengCisco / Telemetry_Receiver

GRPC Update Info:

If use GRPC not TCP/UDP, that will have standard function, you will not need to write “DECODE_FN_MAP…”, function will auto generate, direct to use. Simple list steps:

1. Get GRPC protobuf (e.g “mdt_grpc_dialout”) from cisco / bigmuddy-network-telemetry-proto
2. Install/use compile tools, suggest install python virtual env, you can reference 在MacOS中部署Python虚拟开发环境

(telemetry-protocol) [root@telemetry telemetry-protocol]# python -V
Python 3.6.8
(telemetry-protocol) [root@telemetry telemetry-protocol]# easy_install pip
(telemetry-protocol) [root@telemetry telemetry-protocol]# pip install grpcio
(telemetry-protocol) [root@telemetry telemetry-protocol]# pip install protobuf
(telemetry-protocol) [root@telemetry telemetry-protocol]# pip install grpcio_tools
(telemetry-protocol) [root@telemetry telemetry-protocol]# python -m grpc_tools.protoc -I. --python_out=. --grpc_python_out=. cisco_grpc_dialout.proto
(telemetry-protocol) [root@telemetry telemetry-protocol]# ls -l|grep cisco
-rw-r--r--.  1 root    root       2695 Aug 10 16:16 cisco_grpc_dialout_pb2_grpc.py   #generated
-rw-r--r--.  1 root    root       3805 Aug 10 16:16 cisco_grpc_dialout_pb2.py   #generated
-rw-r--r--.  1 root    root        485 Aug 10 16:15 cisco_grpc_dialout.proto   #proto file  

Follow all file if you need grpc protocol:

[root@telemetry grpc-dailout]# ls -l
total 36
-rw-r--r--. 1 root root  2695 Aug 10 16:16 cisco_grpc_dialout_pb2_grpc.py #Contains the server Stub class and the client Stub class, as well as the service RPC interface to be implemented.
-rw-r--r--. 1 root root  3805 Aug 10 16:16 cisco_grpc_dialout_pb2.py #message serialization classes
-rw-r--r--. 1 root root   484 Aug 10 15:36 mdt_grpc_dialout.proto 
-rw-r--r--. 1 root root  3722 Aug 10 16:11 service_grpc_dialout_no_tls.py #service python
-rw-r--r--. 1 root root 19220 Aug 10 15:58 telemetry_pb2.py  #decode gpb-kv messages, generate as below

grpc-dailout.zip

Install Protobuf of python version

完整阅读

Thanks @JianJian‘s sharing how to import global route in IXIA. The article have two part, 1st part was done by IxNetwork original way. 2nd part will done by IXNetwork Scenario (later updste).

Before import, we must have global route table file, we can download from follow lnik:

http://bgp.potaroo.net/as2.0/bgptable.txt

http://bgp.potaroo.net/v6/as2.0/bgptable.txt

完整阅读

• Choose 2-3 router for FAD, but not all router
• Config follows configuration at FAD router:

router isis srte
affinity-map red bit-position 23
flex-algo 128
 priority 200
 metric-type delay
 advertise-definition
 affinity exclude-any red

• Config follows configuration at exclude/include function router:

router isis srte
affinity-map red bit-position 23
flex-algo 128
 metric-type delay <-- define in FAD
 affinity exclude-any red
!
inter gix/x/x/x
 affinity flex-algo red

• Config follows configuration at normal router:

router isis srte
flex-algo 128
  metric-type delay <-- define in FAD