Very Computer

I have been connecting my laptop to my home network through a switch on
eth0. Works well and picks up an IP address from dhcpd. Recently I added
a second ethernet card (eth1) to my linux 2.2.21 box and started to plug
in the laptop through that (crossover cable). It was working last week
but today the logs are calling it a martian and refusing me access to
the network drives.

Snippet from /var/log/messages:

Aug  2 13:36:33 stargate kernel: martian source c800040a for c800040a,
 dev eth1
Aug  2 13:36:33 stargate kernel: ll header: ff ff ff ff ff ff 00 02 a5
 9a d2 15 08 06
Aug  2 13:36:34 stargate kernel: martian source c800040a for c800040a,
 dev eth1
Aug  2 13:36:34 stargate kernel: ll header: ff ff ff ff ff ff 00 02 a5
 9a d2 15 08 06
Aug  2 13:36:35 stargate kernel: martian source c800040a for c800040a,
 dev eth1
Aug  2 13:36:35 stargate kernel: ll header: ff ff ff ff ff ff 00 02 a5
 9a d2 15 08 06
Aug  2 13:37:00 stargate kernel: martian source c800040a for ffff050a,
 dev eth1
Aug  2 13:37:00 stargate kernel: ll header: ff ff ff ff ff ff 00 02 a5
 9a d2 15 08 00

I have the following at the beginning of my ipchains script to catch
spoofing, etc."

# Hang on long enough to get ppp0 up..
echo 1 > /proc/sys/net/ipv4/ip_dynaddr

# Enable IP Forwarding, if it isn't already
echo 1 > /proc/sys/net/ipv4/ip_forward

# Enable TCP SYN Cookie Protection
echo 1 > /proc/sys/net/ipv4/tcp_syncookies

# Enable always defragging Protection
echo 1 > /proc/sys/net/ipv4/ip_always_defrag

# Enable broadcast echo  Protection
echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts

# Enable bad error message  Protection
echo 1 > /proc/sys/net/ipv4/icmp_ignore_bogus_error_responses

# Enable IP spoofing protection
# turn on Source Address Verification
for f in /proc/sys/net/ipv4/conf/*/rp_filter; do
    echo 1 > $f
done

# Disable ICMP Redirect Acceptance
for f in /proc/sys/net/ipv4/conf/*/accept_redirects; do
    echo 0 > $f
done

# Disable Source Routed Packets
for f in /proc/sys/net/ipv4/conf/*/accept_source_route; do
    echo 0 > $f
done

# Log Spoofed Packets, Source Routed Packets, Redirect Packets
for f in /proc/sys/net/ipv4/conf/*/log_martians; do
    echo 1 > $f
done

What do I have to do to persuade the box that the laptop is OK connecting
on eth1 or eth0?

Thanks,

Graham

IMSMC, it means it is logging packets that have un-routable
source addresses.
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Michael J. Tobler: motorcyclist, surfer,  #    Black holes result
 skydiver, and author: "Inside Linux",     #   when God divides the  
 "C++ HowTo", "C++ Unleashed"              #     universe by zero

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