mogzy Posted November 17, 2009 Posted November 17, 2009 Hi Guys, I've had a quick read around and cant see anything that would help, so I figured id ask I have a redhat linux box with 2 network cards: External [eth0] IPaddress: 192.168.115.10 mask: 255.255.255.0 Gateway: 192.168.115.1 Internal [eth1] IPaddres: 192.168.0.1 mask: 255.255.0.0 Gateway: 192.168.0.254 I can ping and access the machine from internal, but not externally. Initially I thought routing table problems: was it sending the request to the external card and trying to reply with the internal?? Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.115.0 192.168.115.1 255.255.255.0 UG 0 0 0 eth0 192.168.115.0 * 255.255.255.0 U 0 0 0 eth0 169.254.0.0 * 255.255.0.0 U 0 0 0 eth1 192.168.0.0 192.168.0.254 255.255.0.0 UG 0 0 0 eth1 192.168.0.0 * 255.255.0.0 U 0 0 0 eth1 default 192.168.115.1 0.0.0.0 UG 0 0 0 eth0 It doesnt appear so. I figured id try and trace route to its external address. traceroute to 212.248.*.* (212.248.*.*), 30 hops max, 38 byte packets 1 192.168.115.10 (192.168.115.10) 3000.754 ms !H 3000.518 ms !H 3000.391 ms !H Ok - so can it ping itself externally? PING 212.248.*.* (212.248.*.*) 56(84) bytes of data. From 192.168.115.10 icmp_seq=1 Destination Host Unreachable Doesnt appear so. I get the feeling I've been working on this for that long that its a case of cant see the wood for the trees, and im missing somthing really obvious. If anyone has any suggestions or need me to provide more details in order to help then please just ask away. Any help is greatly appreciated. Cheers.
pod Posted November 17, 2009 Posted November 17, 2009 Some routers will not, or are not configured, to connect machines from internal to external and back again. I was tearing my hair out one day trying to do something similar to what you are only to discover that all was setup correctly but I could not connect to my webserver's external ip address from the internal network. This might not be the case, but it would be easy for you to check.
james_yale Posted November 20, 2009 Posted November 20, 2009 Can you ping any other hosts on the 192.168.115.10/24 network, or can they ping your box? What are you actually trying to do with the box?
CyberNerd Posted November 20, 2009 Posted November 20, 2009 External [eth0] IPaddress: 192.168.115.10 mask: 255.255.255.0 Internal [eth1] IPaddres: 192.168.0.1 mask: 255.255.0.0 would it cause a problem that eth0 is within the same subnet as eth1? it looks odd to me.
aggie Posted November 30, 2009 Posted November 30, 2009 would it cause a problem that eth0 is within the same subnet as eth1? it looks odd to me. Network masks are conflicting. The host is going to get confused as to which interface to use to get to 192.168.115.1. If you want to test this take down the internal interface (e.g. ifconfig eth1 down), or unplug it and it will work fine and dandy. I'd suggest using a different internal IP range/netmask if at all possible?
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