Re: Sending ICMP echo request out
anil dahiya <[email protected]> Tue, 13 Dec 2011 10:19:39 +0530
| Newsgroups | gmane.linux.newbie,gmane.comp.security.firewalls.netfilter.general,gmane.linux.network.general |
|---|---|
| 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]> w= rote: > =F7 =F0=D4., 09/12/2011 =D7 00:00 +0530, anil dahiya =D0=C9=DB=C5=D4: >> Hi , >> >> I have following setup with routing table as shown below: >> >> +-----------------------+ >> | =9A =9ASystem-1 =9A =9A =9A| >> | =9A =9A "client" =9A =9A =9A =9A | >> |------------------------| >> | =9A192.168.11.5 =9A | >> +----------------------+ >> =9A =9A =9A =9A| >> =9A =9A =9A =9A| >> +------+-----+ >> | =9A Switch =9A +----------------------+ >> +------+-----+ =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A| >> =9A =9A =9A =9A| =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A= =9A =9A =9A | >> =9A =9A =9A =9A| =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A +------= -------------------+ >> =9A =9A =9A =9A| =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A| =9A= 192.168.11.1 =9A =9A =9A| >> =9A =9A =9A =9A| =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A|---= ------------------------| >> =9A =9A =9A =9A| =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A| =9A= =9A Router =9A =9A =9A =9A =9A =9A| >> =9A =9A =9A =9A| =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A|---= ----------------------- | >> =9A =9A =9A =9A| =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A| =9A= 192.168.12.1 =9A =9A | >> =9A =9A =9A =9A| =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A +------= --------------------+ >> =9A =9A =9A =9A| =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A= =9A =9A =9A =9A =9A| >> =9A =9A =9A =9A| =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A= =9A =9A =9A =9A =9A| >> +------------------------+ =9A =9A =9A =9A =9A =9A =9A =9A| >> | =9A192.168.11.6 =9A =9A =9A| =9A =9A =9A =9A =9A =9A =9A =9A| >> |--------------------------| =9A =9A =9A =9A =9A =9A =9A =9A| >> | =9A System-2 =9A =9A =9A =9A| =9A =9A =9A =9A =9A =9A =9A =9A| >> |--------------------------| =9A =9A =9A =9A =9A =9A =9A =9A| >> | =9A 192.168.12.6 =9A =9A| =9A =9A =9A =9A =9A =9A =9A =9A| >> | =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A =9A|--------------= --+ >> +------------------------+ >> >> Routing table details of setup >> ------------------------------------------ >> System-1 >> ----- >> $route -n >> Kernel IP routing table >> Destination =9A =9A Gateway =9A =9A =9A =9A Genmask =9A =9A =9A =9A = =46lags Metric Ref =9A =9AUse Iface >> 192.168.11.0 =9A =9A0.0.0.0 =9A =9A =9A =9A 255.255.255.0 =9A U =9A = =9A 1 =9A =9A =9A0 =9A =9A =9A =9A0 eth1 >> 0.0.0.0 =9A =9A =9A =9A 192.168.11.1 =9A =9A0.0.0.0 =9A =9A =9A =9A = UG =9A =9A0 =9A =9A =9A0 =9A =9A =9A =9A0 eth1 >> >> >> Router >> ----------- >> $route -n >> Kernel IP routing table >> Destination =9A =9A Gateway =9A =9A =9A =9A Genmask =9A =9A =9A =9A = =46lags Metric Ref =9A =9AUse Iface >> 192.168.12.0 =9A =9A0.0.0.0 =9A =9A =9A =9A 255.255.255.0 =9A U =9A = =9A 0 =9A =9A =9A0 =9A =9A =9A =9A0 eth1 >> 192.168.11.0 =9A =9A0.0.0.0 =9A =9A =9A =9A 255.255.255.0 =9A U =9A = =9A 0 =9A =9A =9A0 =9A =9A =9A =9A0 eth0 >> >> >> System-2 >> ------ >> $route -n >> Kernel IP routing table >> Destination =9A =9A Gateway =9A =9A =9A =9A Genmask =9A =9A =9A =9A = =46lags Metric Ref =9A =9AUse Iface >> 192.168.12.0 =9A =9A0.0.0.0 =9A =9A =9A =9A 255.255.255.0 =9A U =9A = =9A 0 =9A =9A =9A0 =9A =9A =9A =9A0 eth1 >> 192.168.11.0 =9A =9A0.0.0.0 =9A =9A =9A =9A 255.255.255.0 =9A U =9A = =9A 0 =9A =9A =9A0 =9A =9A =9A =9A0 eth0 >> 0.0.0.0 =9A =9A =9A =9A 192.168.12.1 =9A =9A0.0.0.0 =9A =9A =9A =9A = UG =9A =9A0 =9A =9A =9A0 =9A =9A =9A =9A0 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 bu= t >> system is not sending any response to 192.168.11.5 using either of N= IC >> 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 =9Ahttp://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