ping to internet

[ahmad82pkn]

Hi,

I know my concept is wrong, so that is why  i am here to get guidance from experts :)

When i ping internet with 1500 bytes payload  with DF bit set, I know i am hitting 1528 which is more than 1500 bytes and ping doesnt work.

But i thought when i will disable DF bit then ping will work ? But still it doesnt work, why ?

[Linux]$ ping 172.217.25.164 -s 1500
PING 172.217.25.164 (172.217.25.164) 1500(1528) bytes of data.
From 172.31.0.1 icmp_seq=1 Frag needed and DF set (mtu = 1500)
^C
--- 172.217.25.164 ping statistics ---
13 packets transmitted, 0 received, +1 errors, 100% packet loss, time 12087ms

[Linux]$ ping 172.217.25.164 -s 1500 -M dont
PING 172.217.25.164 (172.217.25.164) 1500(1528) bytes of data.
^C
--- 172.217.25.164 ping statistics ---
12 packets transmitted, 0 received, 100% packet loss, time 10999ms

[Julio E. Moisa]

Hi

You probably need to enable jumbo frames on your device, Usually the MTU is configured to 1500 on the devices and on the ISP side. Please visit this site, it could be useful.

https://supportforums.cisco.com/document/10811/how-configure-jumbo-or-giant-frame-support-cisco-catalyst-switch

Hope it is useful

:-)

[ahmad82pkn]

shouldn't my source pc just fragment the pack and make 2 packets and ping start working ? that is what i was expecting , since df bit is off?