A good site already explains it very well: http://largebgpcommunities.net/
Luckly many vendors and networking software authors are approaching this solution and started implementing the draft. This repository (presumptuously) wants to offer some hints to quickly have a bgp-large-communities-aware lab up & running on the basis of the latest code available.
Currently it supports the following products:
Docker images have been built in order to have them running on the latest BGP-Large-Communities-aware code fetched from the master branch of them.
These images have been created with the only purpose of being used in a "playground", for labs and interoperability tests. They do not implement any security best practice. Use them at your own risk.
I used this Playground to run some interoperability tests and to verify implemented features among the covered tools: here are my findings.
# git clone https://github.com/pierky/bgp-large-communities-playground.git
# cd bgp-large-communities-playground/
# docker network create --subnet=192.0.2.0/24 bgp-large-communities-playground
# docker run --net bgp-large-communities-playground --ip 192.0.2.2 --hostname=exabgp -d -v `pwd`/exabgp:/etc/exabgp:rw pierky/exabgp
# docker run --net bgp-large-communities-playground --ip 192.0.2.3 --hostname=gobgp -d -v `pwd`/gobgp:/etc/gobgp:rw pierky/gobgp
# docker run --net bgp-large-communities-playground --ip 192.0.2.4 --hostname=bird -d -v `pwd`/bird:/etc/bird:rw pierky/bird
# docker run --net bgp-large-communities-playground --ip 192.0.2.5 --hostname=pmacct -d -v `pwd`/pmacct:/etc/pmacct:rw pierky/pmacct
# docker run --net bgp-large-communities-playground --ip 192.0.2.6 --hostname=quagga -d -v `pwd`/quagga:/etc/quagga:rw pierky/quagga
This is enough to create a virtual network, have ExaBGP running on 192.0.2.2, GoBGP on 192.0.2.3, BIRD on 192.0.2.4 and Quagga on 192.0.2.6. The startup config files (exabgp/exabgp.conf, gobgp/gobgp.conf, bird/bird.conf and quagga/quagga.conf) allow these instances to establish BGP sessions:
# cat exabgp/log
...
Thu, 14 Sep 2016 17:54:57 5 network Connected to peer neighbor 192.0.2.3 local-ip 192.0.2.2 local-as 65536 peer-as 65537 router-id 192.0.2.2 family
# cat gobgp/log
...
time="2016-09-14T17:54:57Z" level=info msg="Peer Up" Key=192.0.2.2 State="BGP_FSM_OPENCONFIRM" Topic=Peer
time="2016-09-14T17:54:57Z" level=info msg="Peer Up" Key=192.0.2.4 State="BGP_FSM_OPENCONFIRM" Topic=Peer
The BGP daemon built into pmacct is started too: ExaBGP is configured to setup a neighborship with it and to announce some prefixes:
# cat pmacct/log
...
INFO ( default/core/BGP ): [192.0.2.2] BGP peers usage: 1/2
INFO ( default/core/BGP ): [192.0.2.2] Capability: MultiProtocol [1] AFI [1] SAFI [1]
INFO ( default/core/BGP ): [192.0.2.2] Capability: 4-bytes AS [41] ASN [65536]
INFO ( default/core/BGP ): [192.0.2.2] BGP_OPEN: Asn: 65536 HoldTime: 180
# cat pmacct/bgp.log
{"event_type": "dump_init", "dump_period": 60}
{"event_type": "dump", "ip_prefix": "192.0.2.2/32", ..., "lcomms": "65536:1:1", ...}
{"event_type": "dump", "ip_prefix": "192.0.2.3/32", ..., "lcomms": "65537:1:1", ...}
{"event_type": "dump", "ip_prefix": "192.0.2.4/32", ..., "lcomms": "65538:1:1", ...}
{"event_type": "dump_close", "entries": 3, "tables": 1}
Commands can be run on the instances interactively, by attaching a new terminal to the Docker container, or directly from the host:
# # take note of the container ID of each instance
# docker ps
CONTAINER ID IMAGE ...
ff5c323d2118 pierky/gobgp ...
2c46decfb88a pierky/exabgp ...
...
# docker exec -it ff5c323d2118 bash
root@gpbgp:/go# gobgp neighbor
Peer AS Up/Down State |#Advertised Received Accepted
192.0.2.2 65536 00:02:19 Establ | 0 1 1
192.0.2.4 65538 00:01:57 Establ | 1 1 1
root@gpbgp:/go# exit
exit
# docker exec -it ff5c323d2118 gobgp global
AS: 65537
Router-ID: 192.0.2.3
Listening Port: 179, Addresses: 0.0.0.0, ::
MPLS Label Range: 16000..1048575
Since ExaBGP's config file contains a static route which is tagged with a BGP Large Community we can verify how GoBGP and BIRD see it:
# docker exec ff5c323d2118 gobgp neighbor 192.0.2.2 adj-in
Network Next Hop AS_PATH Age Attrs
203.0.113.1/32 192.0.2.2 65536 00:14:49 [{Origin: i} {LargeCommunity: [ 65536:1:2]}]
# docker exec 153b6165385f birdcl show route all
BIRD 1.6.1 ready.
203.0.113.1/32 unreachable [ExaBGP 14:29:25 from 192.0.2.2] * (100/-) [AS65536i]
Type: BGP unicast univ
BGP.origin: IGP
BGP.as_path: 65536
BGP.next_hop: 192.0.2.2
BGP.local_pref: 100
BGP.large_community: (65536,1,2)
unreachable [GoBGP 14:29:28 from 192.0.2.3] (100/-) [AS65536i]
Type: BGP unicast univ
BGP.origin: IGP
BGP.as_path: 65537 65536
BGP.next_hop: 192.0.2.3
BGP.local_pref: 100
BGP.large_community: (65536,1,2)
LargeCommunity: [ 65536:1:2], BGP.large_community: (65536,1,2) - here it is!
Let's have GoBGP announce a new tagged prefix and see how ExaBGP receive it:
# docker exec ff5c323d2118 gobgp global rib add -a ipv4 203.0.113.2/32 large-community 65537:3:4
# cat exabgp/log
...
Thu, 14 Sep 2016 18:15:18 5 routes peer 192.0.2.3 ASN 65537 << UPDATE (1) ( 4) attributes origin incomplete as-path [ 65537 ] large-community 65537:3:4
Similarly we can send a ping from one of the running containers to pmacct host to see how it handles large communities in its output:
# docker exec -it ff5c323d2118 bash
root@gobgp:/go# ping 192.0.2.5
PING 192.0.2.5 (192.0.2.5): 56 data bytes
64 bytes from 192.0.2.5: icmp_seq=0 ttl=64 time=0.185 ms
64 bytes from 192.0.2.5: icmp_seq=1 ttl=64 time=0.131 ms
64 bytes from 192.0.2.5: icmp_seq=2 ttl=64 time=0.125 ms
# cat pmacct/plugin1.out
LCOMMS,SRC_LCOMMS,SRC_IP,DST_IP,SRC_PORT,DST_PORT,PROTOCOL,PACKETS,BYTES
,65537:1:1,192.0.2.3,192.0.2.5,0,0,icmp,3,252
65537:1:1,,192.0.2.5,192.0.2.3,0,0,icmp,3,252
Since all the images EXPOSE port 179, the -p 179:179 Docker run option can be used to publish the BGP daemon outside the local host, in order to test interoperability with other software/hardware:
# docker run --net bgp-large-communities-playground --ip 192.0.2.3 -p 179:179 --hostname=gpbgp -d -v `pwd`/gobgp:/etc/gobgp:rw pierky/gobgp
# # now establish a BGP session with <your_host_ip>:179
Enjoy BGP Large Communities and have fun! ;)
Pier Carlo Chiodi - https://pierky.com
Blog: https://blog.pierky.com Twitter: @pierky