Re: Bogus frames transmitted with r8169 & fragmentation & large mtu

Francois Romieu
2012-02-16T12:17:16Z

Francois Romieu <romieu@fr.zoreil.com> :
[...]
> I am testing it now.

It does not fix the problem. It seems to make a difference but I still
see a few percents packet loss. The pattern has changed a bit too: there
are more bogus IP fragment offsets.

Trying with 'ping -qf -c 100 -l 2 -s 65507 10.0.7.1'

Good:

239 0.020107 10.0.7.1 -> 10.0.7.5 IP Fragmented IP protocol (proto=ICMP 0x01, off=0, ID=9f97)
240 0.020116 10.0.7.1 -> 10.0.7.5 IP Fragmented IP protocol (proto=ICMP 0x01, off=8976, ID=9f97)
241 0.020122 10.0.7.1 -> 10.0.7.5 IP Fragmented IP protocol (proto=ICMP 0x01, off=17952, ID=9f97)
242 0.020128 10.0.7.1 -> 10.0.7.5 IP Fragmented IP protocol (proto=ICMP 0x01, off=26928, ID=9f97)
243 0.020134 10.0.7.1 -> 10.0.7.5 IP Fragmented IP protocol (proto=ICMP 0x01, off=35904, ID=9f97)
244 0.020139 10.0.7.1 -> 10.0.7.5 IP Fragmented IP protocol (proto=ICMP 0x01, off=44880, ID=9f97)
245 0.020145 10.0.7.1 -> 10.0.7.5 IP Fragmented IP protocol (proto=ICMP 0x01, off=53856, ID=9f97)
246 0.020150 10.0.7.1 -> 10.0.7.5 ICMP Echo (ping) reply (id=0x04c7, seq(be/le)=16/4096, ttl=64)

Bad:

247 0.020809 10.0.7.5 -> 10.0.7.1 IP Fragmented IP protocol (proto=ICMP 0x01, off=0, ID=dce9)
248 0.020977 10.0.7.5 -> 10.0.7.1 IP Fragmented IP protocol (proto=ICMP 0x01, off=8976, ID=dce9)
249 0.021046 10.0.7.5 -> 10.0.7.1 IP Fragmented IP protocol (proto=ICMP 0x01, off=17952, ID=dce9)
250 0.021192 10.0.7.5 -> 10.0.7.1 IP Fragmented IP protocol (proto=ICMP 0x01, off=26928, ID=dce9)
251 0.021199 10.0.7.5 -> 10.0.7.1 IP Fragmented IP protocol (proto=ICMP 0x01, off=35904, ID=dce9)
252 0.021291 10.0.7.5 -> 10.0.7.1 IP Fragmented IP protocol (proto=ICMP 0x01, off=44880, ID=dce9)
253 0.021298 10.0.7.5 -> 10.0.7.1 IP Fragmented IP protocol (proto=ICMP 0x01, off=62832, ID=dce9)

So far I have only seen it with the 2nd and last fragment.

--
Ueimor