i have set /proc/sys/net/ipv4/ip_no_pmtu_disc to 2
Path MTU discovery value Meaning IP_PMTUDISC_WANT Use per-route settings. IP_PMTUDISC_DONT Never do Path MTU Discovery. IP_PMTUDISC_DO Always do Path MTU Discovery. IP_PMTUDISC_PROBE Set DF but ignore Path MTU.
now when i have set mtu to 400 and send 1000 bytes via simple client server code , i don't see fragmentation in tcpdump , what can be the issue here?