In my server, I have 2 public interfaces with 2 public IPs and 1 has private IP too.
eno1 - 149.20.185.126 (public), 10.2.2.2 (private)
eno2 - 149.20.185.54 (public)
For some other work (DPDK bind) I need to down the eno1 interface for some time and then up again. Then I found out that even a normal ifconfig restart caused network issues.
I did ssh connect via 149.20.185.154(eno2) and then restarted ("ifconfig eno1 down" & "ifconfig eno1 up") the eno1 interface.
- Sometimes the IP 149.20.185.126(eno1) immediately gets responding but
- sometimes not (I kept doing ping from other servers to check).
- Sometimes this IP gets unavailable after even 20-30 minutes of interface restart and again gets available.
Whenever it gets unavailable after interface restart I tried restarting networking services but same but the IP doesn't get online immediately. Though server reboot solves all the problems, I want to avoid this.
I also checked routing table and it's the same after interface restart so it isn't causing problem for sure..! As I was told Cent OS is not showing this issue. Is this Ubuntu issue or I am doing something wrong while restarting interface?
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 149.20.185.1 0.0.0.0 UG 0 0 0 eno2
0.0.0.0 149.20.185.1 0.0.0.0 UG 0 0 0 eno1
10.2.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eno1
149.20.185.0 0.0.0.0 255.255.255.128 U 0 0 0 eno2
149.20.185.0 0.0.0.0 255.255.255.128 U 0 0 0 eno1
default via 149.20.185.1 dev eno2 proto static
default via 149.20.185.1 dev eno1 proto static
10.2.2.0/24 dev eno1 proto kernel scope link src 10.2.2.2
149.20.185.0/25 dev eno2 proto kernel scope link src 149.20.185.54
149.20.185.0/25 dev eno1 proto kernel scope link src 149.20.185.126
