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Old 01-12-2008, 07:27 AM   #1
AndrewP
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Registered: Aug 2004
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Question External traffic


Just set up a new home server with CentOS 5.1 and I can't get the connection working properly - any traffic that is not from a directly connected network is dropped.

The physical setup is my ADSL router being a transparent bridge to the server (eth1), which is also connected to my internal network (eth0) and it should be acting as a firewall, network and file server. The new one is replacing my existing server (running CentOS 4.2). I've a /30 from my ISP, the router has one of the available addresses and the server the other.

I can ping and generally connect to my router and internal network, but any traffic that comes from outside of that isn't received properly - it shows up in a tcpdump running on the interface but isn't received by the browser/command line tool etc. The firewall was my (obvious?) first thought, but it's the same iptables script as on my existing server, and I've also tried flushing all the rules and also stopping iptables completely and the problem persists.

Any ideas? I'm fairly sure I've got the basic network configuration correct but if you need any more info just ask, and thanks in advance .
 
Old 01-12-2008, 01:29 PM   #2
bmarx
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what does the routing table on the server look like? Is there a default route?
 
Old 01-12-2008, 03:14 PM   #3
AndrewP
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route gives
Code:
Kernel IP routing table 
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface 
<externalID>    *               255.255.255.252 U     0      0        0 eth1 
192.168.0.0     *               255.255.254.0   U     0      0        0 eth0 
169.254.0.0     *               255.255.0.0     U     0      0        0 eth1 
default         <routerIP>      0.0.0.0         UG    0      0        0 eth1
The route seems to be working, traffic flows out and back in but after it's received nothing happens.
 
Old 01-13-2008, 02:29 PM   #4
AndrewP
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Unhappy

After incoming data is received (and seen in tcpdump) it gets silently dropped somewhere. I strace'd a ping and got
Code:
recvmsg(3, ...) = -1 EAGAIN (Resource temporarily unavailable)
when I could see the icmp echo replies in tcdump.

Properly stuck now
 
  


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