Hello, I am new to network routing and I need help configuring a linux box with two ethernet cards. In this case it''s a Linux RH 7.3 box, in a cabinet that already has a couple of Windows servers. The Windows server routing is below as an example. The Linux box has an out-of-band interface at 10.130.36.38 and a public eth at 62.50.8.84. I had to add a route for the private interface so I could access its ports. However, since I did that, the Linux box cannot access the internet. The incoming requests to 62.50.8.84 are fine, I can hit the web service fine, but the net is not visible from the linux box. I think it''s just a matter of adding a route but am not sure how. Interestingly enough I can ping the outside machines but cannot browse over the net. I remember that this worked fine before I added the route to the private interface, so it must be a routing problem and not some other issue. The Linux routing table: [root@sylvester root]# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 62.50.8.80 0.0.0.0 255.255.255.248 U 0 0 0 eth0 10.130.36.32 0.0.0.0 255.255.255.240 U 0 0 0 eth1 172.17.1.0 10.130.36.34 255.255.255.240 UG 0 0 0 eth1 10.0.0.0 10.130.36.33 255.0.0.0 UG 0 0 0 eth1 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo 0.0.0.0 62.50.8.81 0.0.0.0 UG 0 0 0 eth0 [root@sylvester root]# ip route 62.50.8.80/29 dev eth0 scope link 10.130.36.32/28 dev eth1 scope link 172.17.1.0/28 via 10.130.36.34 dev eth1 10.0.0.0/8 via 10.130.36.33 dev eth1 127.0.0.0/8 dev lo scope link default via 62.50.8.81 dev eth0 The Windows server routing, which works fine: [c:\4nt]route PRINT ========================================================================== Interface List 0x1 ........................... MS TCP Loopback interface 0x2 ...44 45 53 54 42 00 ...... NOC Extranet Access Adapter 0x1000004 ...00 0b cd 1c 99 84 ...... Compaq NC7780 Gigabit Server Adapter 0x1000005 ...00 0b cd 1c 96 95 ...... Compaq NC7780 Gigabit Server Adapter ========================================================================== ========================================================================== Active Routes: Network Destination Netmask Gateway Interface Metric 0.0.0.0 0.0.0.0 62.50.8.81 62.50.8.83 1 10.0.0.0 255.0.0.0 10.130.36.33 10.130.36.36 1 10.130.36.32 255.255.255.240 10.130.36.36 10.130.36.36 1 10.130.36.36 255.255.255.255 127.0.0.1 127.0.0.1 1 10.255.255.255 255.255.255.255 10.130.36.36 10.130.36.36 1 62.50.0.221 255.255.255.255 10.130.36.33 10.130.36.36 1 62.50.0.222 255.255.255.255 10.130.36.33 10.130.36.36 1 62.50.8.80 255.255.255.248 62.50.8.83 62.50.8.83 1 62.50.8.83 255.255.255.255 127.0.0.1 127.0.0.1 1 62.255.255.255 255.255.255.255 62.50.8.83 62.50.8.83 1 127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1 172.17.1.0 255.255.255.240 10.130.36.34 10.130.36.36 1 224.0.0.0 224.0.0.0 10.130.36.36 10.130.36.36 1 224.0.0.0 224.0.0.0 62.50.8.83 62.50.8.83 1 255.255.255.255 255.255.255.255 62.50.8.83 2 1 Default Gateway: 62.50.8.81 ========================================================================== Persistent Routes: Network Address Netmask Gateway Address Metric 10.0.0.0 255.0.0.0 10.130.36.33 1 62.50.0.221 255.255.255.255 10.130.36.33 1 62.50.0.222 255.255.255.255 10.130.36.33 1 172.17.1.0 255.255.255.240 10.130.36.34 1 Any help would be appreciated. Eduard _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
I''ll take a stab at this . . . Try a traceroute to your ISP''s DNS server or even the ISP''s gateway to you. (This is the next hop beyond your onsite gateway to the world.) This will tell you what interface your stuff chooses when you want to go out to the public Internet. Also check your firewall rules on this box (iptables -L -v -n) to see if you''re blocking anything. And also look to see if you have any alternate routing tables going on (ip rule list and stuff like that). - Greg Scott -----Original Message----- From: lartc-admin@mailman.ds9a.nl [mailto:lartc-admin@mailman.ds9a.nl] On Behalf Of eduard@technios.com Sent: Friday, January 30, 2004 3:06 AM To: lartc@mailman.ds9a.nl Cc: eduard@technios.com Subject: [LARTC] Multihome routing question Hello, I am new to network routing and I need help configuring a linux box with two ethernet cards. In this case it''s a Linux RH 7.3 box, in a cabinet that already has a couple of Windows servers. The Windows server routing is below as an example. The Linux box has an out-of-band interface at 10.130.36.38 and a public eth at 62.50.8.84. I had to add a route for the private interface so I could access its ports. However, since I did that, the Linux box cannot access the internet. The incoming requests to 62.50.8.84 are fine, I can hit the web service fine, but the net is not visible from the linux box. I think it''s just a matter of adding a route but am not sure how. Interestingly enough I can ping the outside machines but cannot browse over the net. I remember that this worked fine before I added the route to the private interface, so it must be a routing problem and not some other issue. The Linux routing table: [root@sylvester root]# route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 62.50.8.80 0.0.0.0 255.255.255.248 U 0 0 0 eth0 10.130.36.32 0.0.0.0 255.255.255.240 U 0 0 0 eth1 172.17.1.0 10.130.36.34 255.255.255.240 UG 0 0 0 eth1 10.0.0.0 10.130.36.33 255.0.0.0 UG 0 0 0 eth1 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo 0.0.0.0 62.50.8.81 0.0.0.0 UG 0 0 0 eth0 [root@sylvester root]# ip route 62.50.8.80/29 dev eth0 scope link 10.130.36.32/28 dev eth1 scope link 172.17.1.0/28 via 10.130.36.34 dev eth1 10.0.0.0/8 via 10.130.36.33 dev eth1 127.0.0.0/8 dev lo scope link default via 62.50.8.81 dev eth0 The Windows server routing, which works fine: [c:\4nt]route PRINT ========================================================================= Interface List 0x1 ........................... MS TCP Loopback interface 0x2 ...44 45 53 54 42 00 ...... NOC Extranet Access Adapter 0x1000004 ...00 0b cd 1c 99 84 ...... Compaq NC7780 Gigabit Server Adapter 0x1000005 ...00 0b cd 1c 96 95 ...... Compaq NC7780 Gigabit Server Adapter ========================================================================= ========================================================================= Active Routes: Network Destination Netmask Gateway Interface Metric 0.0.0.0 0.0.0.0 62.50.8.81 62.50.8.83 1 10.0.0.0 255.0.0.0 10.130.36.33 10.130.36.36 1 10.130.36.32 255.255.255.240 10.130.36.36 10.130.36.36 1 10.130.36.36 255.255.255.255 127.0.0.1 127.0.0.1 1 10.255.255.255 255.255.255.255 10.130.36.36 10.130.36.36 1 62.50.0.221 255.255.255.255 10.130.36.33 10.130.36.36 1 62.50.0.222 255.255.255.255 10.130.36.33 10.130.36.36 1 62.50.8.80 255.255.255.248 62.50.8.83 62.50.8.83 1 62.50.8.83 255.255.255.255 127.0.0.1 127.0.0.1 1 62.255.255.255 255.255.255.255 62.50.8.83 62.50.8.83 1 127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1 172.17.1.0 255.255.255.240 10.130.36.34 10.130.36.36 1 224.0.0.0 224.0.0.0 10.130.36.36 10.130.36.36 1 224.0.0.0 224.0.0.0 62.50.8.83 62.50.8.83 1 255.255.255.255 255.255.255.255 62.50.8.83 2 1 Default Gateway: 62.50.8.81 ========================================================================= Persistent Routes: Network Address Netmask Gateway Address Metric 10.0.0.0 255.0.0.0 10.130.36.33 1 62.50.0.221 255.255.255.255 10.130.36.33 1 62.50.0.222 255.255.255.255 10.130.36.33 1 172.17.1.0 255.255.255.240 10.130.36.34 1 Any help would be appreciated. Eduard _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/ _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
Thanks for the suggestions. I noticed that traceroute just gives me a timeout on the first hop (the local gateway). In a similar test on the working machine, the local gateway responds perfectly well. Same result is given with "lft" tracing agent. Furthermore, in a frenzy to try to correct this problem, I ended up removing iptables/ipchains from the server. I won''t be able to try your suggestions now... but I spoke to the hosting company and they suggested that I should request a Firewall change on their security appliance. I think that there was a configuration change on their firewall, that''s going to be handled later, for now there''s not much I can do. Thanks again, Eduard> I''ll take a stab at this . . . > > Try a traceroute to your ISP''s DNS server or even the ISP''s gateway to > you. (This is the next hop beyond your onsite gateway to the world.) > This will tell you what interface your stuff chooses when you want to > go out to the public Internet. Also check your firewall rules on this > box (iptables -L -v -n) to see if you''re blocking anything. And also > look to see if you have any alternate routing tables going on (ip rule > list and stuff like that). > > - Greg Scott > > > -----Original Message----- > From: lartc-admin@mailman.ds9a.nl [mailto:lartc-admin@mailman.ds9a.nl] > On Behalf Of eduard@technios.com > Sent: Friday, January 30, 2004 3:06 AM > To: lartc@mailman.ds9a.nl > Cc: eduard@technios.com > Subject: [LARTC] Multihome routing question > > > Hello, > > I am new to network routing and I need help configuring a linux box > with two ethernet cards. In this case it''s a Linux RH 7.3 box, in a > cabinet that already has a couple of Windows servers. The Windows > server routing is below as an example. > > The Linux box has an out-of-band interface at 10.130.36.38 and a public > eth at 62.50.8.84. I had to add a route for the private interface so I > could access its ports. However, since I did that, the Linux box cannot > access the internet. The incoming requests to 62.50.8.84 are fine, I > can hit the web service fine, but the net is not visible from the linux > box. I think it''s just a matter of adding a route but am not sure how. > > Interestingly enough I can ping the outside machines but cannot browse > over the net. I remember that this worked fine before I added the route > to the private interface, so it must be a routing problem and not some > other issue. > > The Linux routing table: > > [root@sylvester root]# route -n > Kernel IP routing table > Destination Gateway Genmask Flags Metric Ref Use > Iface > 62.50.8.80 0.0.0.0 255.255.255.248 U 0 0 0 > eth0 > 10.130.36.32 0.0.0.0 255.255.255.240 U 0 0 0 > eth1 > 172.17.1.0 10.130.36.34 255.255.255.240 UG 0 0 0 > eth1 > 10.0.0.0 10.130.36.33 255.0.0.0 UG 0 0 0 > eth1 > 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 > lo > 0.0.0.0 62.50.8.81 0.0.0.0 UG 0 0 0 > eth0 > > [root@sylvester root]# ip route > 62.50.8.80/29 dev eth0 scope link > 10.130.36.32/28 dev eth1 scope link > 172.17.1.0/28 via 10.130.36.34 dev eth1 > 10.0.0.0/8 via 10.130.36.33 dev eth1 > 127.0.0.0/8 dev lo scope link > default via 62.50.8.81 dev eth0 > > > The Windows server routing, which works fine: > > [c:\4nt]route PRINT > =======================================================================> ==> Interface List > 0x1 ........................... MS TCP Loopback interface > 0x2 ...44 45 53 54 42 00 ...... NOC Extranet Access Adapter 0x1000004 > ...00 0b cd 1c 99 84 ...... Compaq NC7780 Gigabit Server Adapter > 0x1000005 ...00 0b cd 1c 96 95 ...... Compaq NC7780 Gigabit Server > Adapter > =======================================================================> ==> > =======================================================================> ==> Active Routes: > Network Destination Netmask Gateway Interface > Metric > 0.0.0.0 0.0.0.0 62.50.8.81 62.50.8.83 > 1 > 10.0.0.0 255.0.0.0 10.130.36.33 10.130.36.36 > 1 > 10.130.36.32 255.255.255.240 10.130.36.36 10.130.36.36 > 1 10.130.36.36 255.255.255.255 127.0.0.1 127.0.0.1 > 1 > 10.255.255.255 255.255.255.255 10.130.36.36 10.130.36.36 > 1 > 62.50.0.221 255.255.255.255 10.130.36.33 10.130.36.36 > 1 62.50.0.222 255.255.255.255 10.130.36.33 10.130.36.36 1 > 62.50.8.80 255.255.255.248 62.50.8.83 62.50.8.83 > 1 62.50.8.83 255.255.255.255 127.0.0.1 127.0.0.1 1 > 62.255.255.255 255.255.255.255 62.50.8.83 62.50.8.83 > 1 > 127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 > 1 > 172.17.1.0 255.255.255.240 10.130.36.34 10.130.36.36 > 1 > 224.0.0.0 224.0.0.0 10.130.36.36 10.130.36.36 > 1 224.0.0.0 224.0.0.0 62.50.8.83 62.50.8.83 1 > 255.255.255.255 255.255.255.255 62.50.8.83 2 > 1 > Default Gateway: 62.50.8.81 > =======================================================================> ==> Persistent Routes: > Network Address Netmask Gateway Address Metric > 10.0.0.0 255.0.0.0 10.130.36.33 1 > 62.50.0.221 255.255.255.255 10.130.36.33 1 > 62.50.0.222 255.255.255.255 10.130.36.33 1 > 172.17.1.0 255.255.255.240 10.130.36.34 1 > > Any help would be appreciated. > Eduard > > > > _______________________________________________ > LARTC mailing list / LARTC@mailman.ds9a.nl > http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/_______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/