Hi Again, After looking more closely on the problem I've seen that the packets which has size 0x05dc(1500) and DF bit set are not been passed between 2 gre end-point on the same system. Its really exciting to see output of tcpdump. http://203.88.135.194/public/greB-dump.txt http://203.88.135.194/public/greC-dump.txt Thanks for your suggession for this problem. -- Sumit > -----Original Message----- > From: linux-net-owner@vger.kernel.org > > Hi All, > I've 2 gre tunnels connectivity between 3 system > > Internal > ----linux1(greA)-----(greB)linux2(greC)------(greD)cisco-router --- > -Internet > > In this setup i cannot access few of sites. These sites > seems DF bit set. > Following is dump on gre tunnel(greA) on my linux1 box. Same data can be > seen on greB on linux2. If I replace linux2 with cisco router then > everything works fine. > Is it something to do with MTU or any other setting? > Strange point to me is > I can access that site from linux1(with lynx) only and only if I set greA > MTU to 1476(or lower)and greB MTU to 1500(or lower), but not from > any client > on my Internal network. I randomly tried with many different MTU settings > and its combinations. At GreD MTU is 1514, and its my ISP so i cannot have > anything to do there. - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html