Alexander Dalloz wrote:
If above you ment last hop as your station, then do you have defined any
iptables rules for icmp handling?
On my Fedora Core 1 installations I can not agree such traceroute behaviour.
Unexpectedly, I -can- reproduce the behavior he describes.
to a RH8.0 system:
[bevan]> traceroute saladin
traceroute to saladin.internal.avlsi.com (10.0.0.45), 30 hops max, 38 byte packets
1 saladin.internal.avlsi.com (10.0.0.45) 0.216 ms 0.253 ms 0.227 ms
to a FC1.3 system:
[bevan]> traceroute wallace
traceroute to wallace.internal.avlsi.com (10.0.0.28), 30 hops max, 38 byte packets
1 wallace.internal.avlsi.com (10.0.0.28) 0.914 ms !<10> 0.169 ms !<10> 0.158 ms !<10>
The traceroute data appears to be returning correctly, although the aforementioned disturbing !<10> entries have been added.
This is using the -stock- iptables configuration, and iptables does indeed appear to be the cause.
to the FC1.3 system with iptables turned off:
[bevan]> traceroute wallace
traceroute to wallace.internal.avlsi.com (10.0.0.28), 30 hops max, 38 byte packets
1 wallace.internal.avlsi.com (10.0.0.28) 0.202 ms 0.182 ms 0.154 ms
/etc/sysconfig/iptables contains (should be stock):
# Firewall configuration written by redhat-config-securitylevel
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A FORWARD -j RH-Firewall-1-INPUT
-A RH-Firewall-1-INPUT -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -p icmp --icmp-type any -j ACCEPT
-A RH-Firewall-1-INPUT -p 50 -j ACCEPT
-A RH-Firewall-1-INPUT -p 51 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
COMMIT
I'd have thought that '-p icmp' line would cover this, but apparantly there's something else at work. I'll try watching both cases with tcpdump to see if I can isolate the difference.
