Ping fail for packet size more than 23000 on Linux 4.9.119-yocto-standard version

shivashankar · 12-04-2018, 11:30 PM

My_device(4.9.119-yocto-standard)---Directly_connected---machine_2

When I ping from machine_2 to my device with a packet size more than 23000, then found 100% packet loss. System parameters looks good (shown below) but unable to figure out the issue.
/proc/sys/net/ipv4/ipfrag_high_thresh = 262144
/proc/sys/net/ipv4/ipfrag_low_thresh = 196608
/proc/sys/net/ipv4/ipfrag_max_dist = 64
/proc/sys/net/ipv4/ipfrag_secret_interval = 0
/proc/sys/net/ipv4/ipfrag_time = 30

ping -s 24000 1.1.1.1 -c 1
PING 1.1.1.1 (1.1.1.1) 24000(24028) bytes of data.

--- 1.1.1.1 ping statistics ---
1 packets transmitted, 0 received, 100% packet loss, time 0ms

How to resolve this issue... Thanks in advance.

smallpond · 12-05-2018, 08:43 AM

MTU for ethernet and Wifi are 1500. Anything larger is non-standard. If you are going through a switch or router, does it support that MTU? Does the receiving end?

jefro · 12-05-2018, 03:16 PM

Are you suggesting that a prior kernel worked and the version does not?

smallpond · 12-05-2018, 09:54 PM

jefro · 12-06-2018, 03:06 PM

I meant the OP in that question.

scasey · 12-06-2018, 03:15 PM

What happens with higher counts?
man ping says this about -w

Code:

Specify a timeout, in seconds, before ping exits regardless of how many packets have been sent or received. In this case ping does not stop after count packet are sent, it waits either for deadline expire  or  until count probes are answered or for some error notification from network.

which implies that ping normally stops after count packets are sent. Maybe you're not allowing enough time for the foreign server to respond?? Just a thought.