Re: Sending ICMP echo request out

anil dahiya <[email protected]>
Newsgroups org.kernel.vger.linux-newbie,org.kernel.vger.netfilter
Message-ID <CAHGPgw3hvXWnbJM=EBKbiN7LKJFbA2hHdiV0==DO_b_CFtJ37g@mail.gmail.com>
Thanks, It was issue of reverse path filtering.

Regards,
Anil

On Fri, Dec 9, 2011 at 1:29 AM, Nikolay S. <[email protected]> wrote:
> ÷ ðÔ., 09/12/2011 × 00:00 +0530, anil dahiya ÐÉÛÅÔ:
>> Hi ,
>>
>> I have following setup with routing table as shown below:
>>
>> +-----------------------+
>> | š šSystem-1 š š š|
>> | š š "client" š š š š |
>> |------------------------|
>> | š192.168.11.5 š |
>> +----------------------+
>> š š š š|
>> š š š š|
>> +------+-----+
>> | š Switch š +----------------------+
>> +------+-----+ š š š š š š š š š š š š|
>> š š š š| š š š š š š š š š š š š š š š š |
>> š š š š| š š š š š š š š š š š +-------------------------+
>> š š š š| š š š š š š š š š š š š| š192.168.11.1 š š š|
>> š š š š| š š š š š š š š š š š š|---------------------------|
>> š š š š| š š š š š š š š š š š š| š š Router š š š š š š|
>> š š š š| š š š š š š š š š š š š|-------------------------- |
>> š š š š| š š š š š š š š š š š š| š 192.168.12.1 š š |
>> š š š š| š š š š š š š š š š š +--------------------------+
>> š š š š| š š š š š š š š š š š š š š š š š š|
>> š š š š| š š š š š š š š š š š š š š š š š š|
>> +------------------------+ š š š š š š š š|
>> | š192.168.11.6 š š š| š š š š š š š š|
>> |--------------------------| š š š š š š š š|
>> | š System-2 š š š š| š š š š š š š š|
>> |--------------------------| š š š š š š š š|
>> | š 192.168.12.6 š š| š š š š š š š š|
>> | š š š š š š š š š š š š š|----------------+
>> +------------------------+
>>
>> Routing table details of setup
>> ------------------------------------------
>> System-1
>> -----
>> $route -n
>> Kernel IP routing table
>> Destination š š Gateway š š š š Genmask š š š š Flags Metric Ref š šUse Iface
>> 192.168.11.0 š š0.0.0.0 š š š š 255.255.255.0 š U š š 1 š š š0 š š š š0 eth1
>> 0.0.0.0 š š š š 192.168.11.1 š š0.0.0.0 š š š š UG š š0 š š š0 š š š š0 eth1
>>
>>
>> Router
>> -----------
>> $route -n
>> Kernel IP routing table
>> Destination š š Gateway š š š š Genmask š š š š Flags Metric Ref š šUse Iface
>> 192.168.12.0 š š0.0.0.0 š š š š 255.255.255.0 š U š š 0 š š š0 š š š š0 eth1
>> 192.168.11.0 š š0.0.0.0 š š š š 255.255.255.0 š U š š 0 š š š0 š š š š0 eth0
>>
>>
>> System-2
>> ------
>> $route -n
>> Kernel IP routing table
>> Destination š š Gateway š š š š Genmask š š š š Flags Metric Ref š šUse Iface
>> 192.168.12.0 š š0.0.0.0 š š š š 255.255.255.0 š U š š 0 š š š0 š š š š0 eth1
>> 192.168.11.0 š š0.0.0.0 š š š š 255.255.255.0 š U š š 0 š š š0 š š š š0 eth0
>> 0.0.0.0 š š š š 192.168.12.1 š š0.0.0.0 š š š š UG š š0 š š š0 š š š š0 eth1
>>
>>
>> When I do ping from system-1 192.168.11.5 to system-2 192.168.12.6 ,
>> ping echo packet is reaching on system-2 through NIC 192.168.12.6 but
>> system is not sending any response to 192.168.11.5 using either of NIC
>> i.e 192.168.11.6 or 192.168.12.6 ? Why this is happening ? Can you
>> help me ?
>>
>> I have observed same type of symtoms when I do SSH from 192.168.11.5
>> to 192.168.12.6
>>
>> FYI,
>> ip_forwarding is enable on router and iptables are no configured on
>> any of system .
>
> I think, reverse path filtering is the problem here.
>
>>
>> Thanks,
>> Anil
>> --
>> To unsubscribe from this list: send the line "unsubscribe netfilter" in
>> the body of a message to [email protected]
>> More majordomo info at šhttp://vger.kernel.org/majordomo-info.html
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-newbie" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.linux-learn.org/faqs
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.