2.4GHz brcm47xx brcmsmac AP Mode defect ping

[anonymous]

Maybe some defect in AP mode/bridge/switch code

1 Wired Client : Linux ipv4: x.2
1 Wireless Client : rt73xx USB Windows 7 64bit : x.243
latest trunk with AP Mode patches (brcmsmac)

from router x.1:
<code>
root@OpenWrt:/# ping 192.168.1.2 -s 1500 -c 2
PING 192.168.1.2 (192.168.1.2): 1500 data bytes
1508 bytes from 192.168.1.2: seq=0 ttl=64 time=1.504 ms
1508 bytes from 192.168.1.2: seq=1 ttl=64 time=1.521 ms

--- 192.168.1.2 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 1.504/1.512/1.521 ms

root@OpenWrt:/# ping 192.168.1.243 -s 1500 -c 2
PING 192.168.1.243 (192.168.1.243): 1500 data bytes
1508 bytes from 192.168.1.243: seq=0 ttl=128 time=2.395 ms
1508 bytes from 192.168.1.243: seq=1 ttl=128 time=4.033 ms

--- 192.168.1.243 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 2.395/3.214/4.033 ms
</code>

from Linux:
<code>
$ ping 192.168.1.243 -s 1468 -c 2
PING 192.168.1.243 (192.168.1.243) 1468(1496) bytes of data.
1476 bytes from 192.168.1.243: icmp_req=1 ttl=128 time=6.72 ms
1476 bytes from 192.168.1.243: icmp_req=2 ttl=128 time=3.05 ms

--- 192.168.1.243 ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1002ms
rtt min/avg/max/mdev = 3.052/4.887/6.722/1.835 ms

$ ping 192.168.1.243 -s 1470 -c 2
PING 192.168.1.243 (192.168.1.243) 1470(1498) bytes of data.

--- 192.168.1.243 ping statistics ---
2 packets transmitted, 0 received, 100% packet loss, time 1007ms
</code>

from Windows: 1468 working; beginning with size 1469 doesnt work exactly like linux

probable side effect: accessing Samba shares doesnt work, Download from an Apache2 running on Linux doesnt work

[hauke]

Does this also happen with b43?

Do you have any other wifi clients does this also happen there?

[anonymous]

I have the exact same problem with same limit of 1468.

[Zajec]

On my BCM4706 with b43 loaded:

Works:

ping -s 23672 192.168.1.1

Doesn't work:

ping -s 23673 192.168.1.1

[ipha <ipha00@…>]

Same problem on my WNR3500L:

.1: Router
.2: Wired
.4: Wireless
.5: Wireless

From Router:

Works: ping -s 1469 192.168.1.2
Works: ping -s 1469 192.168.1.4

From Wired:

Works:       ping -s 1469 192.168.1.1
Works:       ping -s 1468 192.168.1.4
Does't work: ping -s 1469 192.168.1.4

From Wireless:

Works:       ping -s 1469 192.168.1.1
Works:       ping -s 1469 192.168.1.5
Works:       ping -s 1468 192.168.1.2
Does't work: ping -s 1469 192.168.1.2

I did some tests sending data from LAN -> Wireless with netcat and watched it with tcpdump:
Router capture: ​http://pastebin.com/raw.php?i=e2QpM1vm
Wireless capture: ​http://pastebin.com/raw.php?i=PG90vPHi

It looks like packets greater than 1468 sent from LAN -> Wireless are getting dropped somewhere.

[ipha <ipha00@…>]

I've tried it with wl, b43, and brcmsmac and I get the 1468 limit in each.

Looking at ifconfig br-lan is the only one showing dropped packets. Is there any way to enable more detailed logging?

br-lan    Link encap:Ethernet  HWaddr 00:26:F2:BB:7D:8E  
          inet addr:192.168.1.1  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:60068 errors:0 dropped:69 overruns:0 frame:0
          TX packets:240188 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:8022336 (7.6 MiB)  TX bytes:333511193 (318.0 MiB)

[hauke]

This is fixed in r35834.