I have such a topology made of network namespaces and veth pairs:
------ ------ ------ | a1 | | r1 | | r2 | | | a1-eth0-----------r1-eth0 | |r1-eth1--------------r2-eth1| | -----(126.96.36.199/30) (188.8.131.52/30)----(184.108.40.206/30) (220.127.116.11/30)-----
net.ipv4.ip_forward is 1.
I can successfully ping
a1 with the command:
ping -I a1-eth0 -c1 18.104.22.168
Also, I can successfully ping
r1-eth1 interface with the command:
ping -I r1-eth1 -c1 22.214.171.124
But then, why can't I ping
r1-eth0 interface? I get Destination Host Unreachable:
ping -I r1-eth0 -c1 126.96.36.199 PING 188.8.131.52 (184.108.40.206) from 220.127.116.11 r1-eth0: 56(84) bytes of data. From 18.104.22.168 icmp_seq=1 Destination Host Unreachable --- 22.214.171.124 ping statistics --- 1 packets transmitted, 0 received, +1 errors, 100% packet loss, time 0ms
The same way, I cannot ping one interface of router r1 by another interface of this very router:
# here I get Destination Host Unreachable again: ping -I r1-eth0 -c1 126.96.36.199 # here I get Redirect Host(New nexthop: 188.8.131.52): ping -I r1-eth1 -c1 184.108.40.206
Here is the main route table of r1:
ip route default via 220.127.116.11 dev r1-eth1 18.104.22.168/30 dev r1-eth0 proto kernel scope link src 22.214.171.124 126.96.36.199/30 dev r1-eth1 proto kernel scope link src 188.8.131.52
So to me it looks like the problem is that interfaces of the router
r1 cannot communicate between each other. However,
r1 forwards traffic between
Thank you for attention!
I needed to solve the problem discussed above to solve the problem Tc qdisc delay not seen in tcpdump recording. I have found the solution to that problem and I posted there by the link. So I do not need this question anymore and I close it. Thank you everybody for reading and participating!