Despite already being deployed, the routers and subscribers are still not connected to each other. We can test this using ping. Here we try to ping from subscriber-east to router-east:
$ docker exec -ti clab-srlinux-subscriber-east bash
(app-root) bash-4.4# ping 10.1.1.1
PING 10.1.1.1 (10.1.1.1) 56(84) bytes of data.
^C
--- 10.1.1.1 ping statistics ---
10 packets transmitted, 0 received, 100% packet loss, time 9212msIn this file we will configure the network manually, so that all routers and subscribers are connected and reachable anywhere in the network.
For srlinux cli documentation, see https://documentation.nokia.com/srlinux/SR_Linux_HTML_R21-11/SysMgmt_Guide/cli-interface.html
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Enter configuration mode. Srlinux calls this the
candidateconfiguration, in which we can safely make any change of configuration without impacting the router, then apply them all at once, in a single transaction.--{ running }--[ ]-- A:router-east# enter candidate private --{ candidate private private-admin }--[ ]-- A:router-east#
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Configure an interface manually. We will not enter in the details of how the cli works, srlinux has a lot of great documentation available online for this. Let's just enter the desired configuration change manually. This will configure the interface on router-east, which is connected to router-west. We also add the interface to a network instance (~vrf) we create, and name
default. All the network configuration we will deploy on our routers will go into this network instance.--{ candidate private private-admin }--[ ]-- A:router-east# set / interface ethernet-1/1 set / interface ethernet-1/1 admin-state enable set / interface ethernet-1/1 subinterface 0 set / interface ethernet-1/1 subinterface 0 admin-state enable set / interface ethernet-1/1 subinterface 0 ipv4 set / interface ethernet-1/1 subinterface 0 ipv4 admin-state enable set / interface ethernet-1/1 subinterface 0 ipv4 address 10.0.1.1/30 set / network-instance default set / network-instance default admin-state enable set / network-instance default interface ethernet-1/1.0 set / network-instance default protocols set / network-instance default protocols linux set / network-instance default protocols linux import-routes true set / network-instance default protocols linux export-routes true --{ * candidate private private-admin }--[ ]-- A:router-east#
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Visualize the change you are about to push on the router.
--{ +* candidate private private-admin }--[ ]-- A:router-east# diff + interface ethernet-1/1 { + subinterface 0 { + admin-state enable + ipv4 { + admin-state enable + address 10.0.1.1/30 { + } + } + } + } + network-instance default { + admin-state enable + interface ethernet-1/1.0 { + } + protocols { + linux { + import-routes true + export-routes true + } + } + } --{ +* candidate private private-admin }--[ ]-- A:router-east#
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Commit the change and exit configuration mode. The configuration proposed above should be accepted without any issue.
--{ * candidate private private-admin }--[ ]-- A:router-east# commit now All changes have been committed. Leaving candidate mode. --{ + running }--[ ]-- A:router-east#
💡 You can also use
commit stayto stay in candidate mode. -
Check the status of the interface we just configured using the
showcommand.--{ + running }--[ ]-- A:router-east# show interface ethernet-1/1.0 ================================================================================ ethernet-1/1.0 is up Network-instances: * Name: default Encapsulation : null Type : routed IPv4 addr : 10.0.1.1/30 (static, preferred, primary) ================================================================================ --{ + running }--[ ]-- A:router-east#
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Repeat for the three other interfaces, follow the ip plan presented in the topology here below:
- router-east --> subscriber-east
- router-west --> router-east
- router-west --> subscriber-west
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Test connectivity in between the routers. For this we can simply use the ping command. Pay attention to select the correct network instance! The one in which we configured our interfaces.
--{ + running }--[ ]-- A:router-east# ping network-instance default 10.0.1.2 Using network instance default PING 10.0.1.2 (10.0.1.2) 56(84) bytes of data. 64 bytes from 10.0.1.2: icmp_seq=1 ttl=64 time=61.9 ms 64 bytes from 10.0.1.2: icmp_seq=2 ttl=64 time=3.33 ms ^CCommand execution aborted : 'ping network-instance default 10.0.1.2' --{ + running }--[ ]-- A:router-east#If the ping doesn't go through, you probably missed something in the configuration of the interfaces. Try to figure out yourself what is wrong and enjoy the thought that you will learn to automate all of this very soon.
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Configure the interface manually. The subscribers containers are simple linux hosts, as for most linux hosts, we can simply use the
ipcommand. On subscriber east we will execute the following command:(app-root) bash-4.4# ip address add 10.1.1.2/30 dev eth1 (app-root) bash-4.4#
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Repeat for subscriber west with the correct ip.
💡 Check the topology image above to find the correct ip for subscriber west.
- Test connectivity in between subscriber and router. Let's use the
pingcommand again, on the subscriber side this time.(app-root) bash-4.4# ping 10.1.1.1 PING 10.1.1.1 (10.1.1.1) 56(84) bytes of data. 64 bytes from 10.1.1.1: icmp_seq=1 ttl=64 time=2.25 ms 64 bytes from 10.1.1.1: icmp_seq=2 ttl=64 time=2.20 ms ^C --- 10.1.1.1 ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1000ms rtt min/avg/max/mdev = 2.200/2.223/2.246/0.023 ms
At the moment, we can not ping from one subscriber to the other, we still need to do two things for that:
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Configure ospf (on the routers), so that routes towards each subscribers are advertized to each router.
--{ + running }--[ ]-- A:router-east# enter candidate private --{ + candidate private private-admin }--[ ]-- A:router-east# set / network-instance default protocols ospf set / network-instance default protocols ospf instance default set / network-instance default protocols ospf instance default admin-state enable set / network-instance default protocols ospf instance default version ospf-v2 set / network-instance default protocols ospf instance default router-id 172.30.0.4 set / network-instance default protocols ospf instance default area 1.1.1.1 set / network-instance default protocols ospf instance default area 1.1.1.1 interface ethernet-1/1.0 set / network-instance default protocols ospf instance default area 1.1.1.1 interface ethernet-1/1.0 interface-type broadcast set / network-instance default protocols ospf instance default area 1.1.1.1 interface ethernet-1/2.0 set / network-instance default protocols ospf instance default area 1.1.1.1 interface ethernet-1/2.0 interface-type broadcast --{ +* candidate private private-admin }--[ ]-- A:router-east# commit now All changes have been committed. Leaving candidate mode. --{ + running }--[ ]--
💡 A few notes about this configuration:
- We use ospf-v2 as our links are configured with ipv4 addresses, and ospf-v3 doesn't support that.
- We created one area, in which we include all our interfaces, the id of such area doesn't really mather as it is the only one we will ever configure.
- We used as router-id the same ip as the mgmt ip for our router. We could have chosen anything as long as it stays unique amongst the routers we are configuring.
- We add the interfaces to the subscribers in the ospf instance configuration, while we don't actually speak ospf with the subscribers (we don't configure it on the subscriber side). This simplifies the configuration, as the routes to the subscribers will automatically be shared.
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Configure a static route on each subscriber, to make it use the the link toward the router to reach the other subscriber.
(app-root) bash-4.4# ip route add 10.1.2.0/30 via 10.1.1.1 dev eth1 (app-root) bash-4.4#
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Test end-to-end connectivity by reaching one subscriber from the other, again, using
ping.(app-root) bash-4.4# ping 10.1.2.2 PING 10.1.2.2 (10.1.2.2) 56(84) bytes of data. 64 bytes from 10.1.2.2: icmp_seq=1 ttl=62 time=0.296 ms 64 bytes from 10.1.2.2: icmp_seq=2 ttl=62 time=0.254 ms ^C --- 10.1.2.2 ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1060ms rtt min/avg/max/mdev = 0.254/0.275/0.296/0.021 ms
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