The issue is that eBGP session is established but unable to receive any routing in routing table which contains same AS number i.e 65450, Routes with AS 65450 while Advertised from PE & there are 23 items are not visible in CE routing table.
The network topology as follwing:
Handling Process1. Analyzed the information customer feedback, the router on PE include the AS 65450,as following:
Detail of routes from AS 65450 on PE:
*> 10.10.101.0/24 172.16.0.2 0 0 65450 i
*>i10.10.109.0/24 221.120.255.79 0 700 0 65450 i
*>i10.10.110.0/24 221.120.255.79 0 700 0 65450 i
*>i10.10.113.0/24 221.120.255.77 0 700 0 65450 i
*>i10.10.114.0/24 221.120.255.77 0 700 0 65450 i
*>i10.10.121.0/24 221.120.255.76 0 700 0 65450 i
*>i10.10.122.0/24 221.120.255.76 0 700 0 65450 i
*>i10.10.123.0/24 221.120.255.67 0 700 0 65450 i
*>i10.10.124.0/24 221.120.255.67 0 700 0 65450 i
*> 10.10.129.0/24 172.16.0.114 0 0 65450 i
*> 10.10.130.0/24 172.16.0.114 0 0 65450 i
*> 10.10.131.0/24 172.16.0.122 0 0 65450 i
*> 10.10.132.0/24 172.16.0.122 0 0 65450 i
2. According to network topology and the route informtion, by default the eBGP peer will not receive the route which include the same AS in the AS-list(same with your situation) , this is used to avoid the route loop. So this is a normal behaviour.
3. But customer said when they change CE device from Huawei to Cisco, Cisco device is able to recerve all routes which PE is advertising. So we suspend Cisco has some special configuration to do this. So we check if huawei device have some command can reach this requirement. after check and test confirm, we find the solution as following:
bgp 65450
peer 172.16.0.121 as-number 17557
#
ipv4-family unicast
undo synchronization
network 10.10.131.0 255.255.255.0
network 10.10.132.0 255.255.255.0
import-route direct
peer 172.16.0.121 enable
peer 172.16.0.121 allow-as-loop 2 //need to add this command, the parameter 2 is the AS in the AS-list times
And notice that if all the CE devices are AR1220, then all the devices need to add the above command.
Root Causeby default the eBGP peer will not receive the route which include the same AS in the AS-list(same with your situation) , this is used to avoid the route loop. So this is a normal behaviour.Need to add some special command to reach this requirement.
SolutionNeed to add some special command to reach this requirement. As following:
bgp 65450
peer 172.16.0.121 as-number 17557
#
ipv4-family unicast
undo synchronization
network 10.10.131.0 255.255.255.0
network 10.10.132.0 255.255.255.0
import-route direct
peer 172.16.0.121 enable
peer 172.16.0.121 allow-as-loop 2 //need to add this command, the parameter 2 is the AS in the AS-list times
