Re: Linux vs FreeBSD Which is correct.

On 08/17/2011 01:10 PM, Emil S Tantilov wrote:

On Wed, Aug 17, 2011 at 10:03 AM, Stephen Clark[off-list ref]  wrote:
   

quoted

Hello List,

Firstly thank you for your patience.  I am replacing a bunch of FreeBSD
vpn/fw/routers
with a Linux based system.

I have run into a situation where if I ping our HQ the response comes back
on a different
interface than what the request went out on. FreeBSD is happy and says it
got the response,
Linux is not and gives no indication it got a response.
     

Try enabling ARP filtering:
echo 1>  /proc/sys/net/ipv4/conf/all/arp_filter

Just tried it - made no difference.

Thanks.
[root@L101111 ~]# echo 1 > /proc/sys/net/ipv4/conf/all/arp_filterL101111:~
$ ping -I 172.21.76.150 172.21.232.55
PING 172.21.232.55 (172.21.232.55) from 172.21.76.150 : 56(84) bytes of data.
^C

--- 172.21.232.55 ping statistics ---

9 packets transmitted, 0 received, 100% packet loss, time 8238ms

L101111:~
$ sudo tcpdump -nli eth0 icmp
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes
13:19:13.808262 IP 172.21.232.55 > 172.21.76.150: ICMP echo reply, id 19545, seq 6, length 64
13:19:14.807541 IP 172.21.232.55 > 172.21.76.150: ICMP echo reply, id 19545, seq 7, length 64
^C