Another network problem
Adrian McMenamin
lost) but if I ping 192.168.62.255 -b packets come back from 192.168.62.1.
On the otherhand, there seems no way that I can get 192.168.62.1 to ping
192.168.62.123, but it can ping 192.168.62.2.
What are the sorts of things I should be looking at to fix this?
--
Adrian McMenamin
adr...@mcmen.demon.co.uk
Karl Heyes
> My gateway machine 192.168.62.123 cannot ping 192.168.62.1 (all packets get
> lost) but if I ping 192.168.62.255 -b packets come back from 192.168.62.1.
>
> On the otherhand, there seems no way that I can get 192.168.62.1 to ping
> 192.168.62.123, but it can ping 192.168.62.2.
>
> What are the sorts of things I should be looking at to fix this?
You want to run a packet sniffer on the link to see if packets are
getting there and is so if they are being sent back.
The command on linux on monitor the link for ping/ARP requests is
tcpdump -n -i eth0 icmp and arp
you have to let us know what appears. Ideally you want to run on
either end of the link.
karl.
Simon Waters
>
> My gateway machine 192.168.62.123 cannot ping 192.168.62.1 (all packets get
> lost) but if I ping 192.168.62.255 -b packets come back from 192.168.62.1.
>
> On the otherhand, there seems no way that I can get 192.168.62.1 to ping
> 192.168.62.123, but it can ping 192.168.62.2.
>
> What are the sorts of things I should be looking at to fix this?
If there was no (or incorrect) route from 123 to 1 this is
precisely what you would see. The route for broadcasts can be
different based on subnet masks.
I would use "netstat -nr" to check route tables at both ends,
but particularly the gateway end.
"ifconfig" to check check netmasks and broadcast addresses are
consistent.
Otherwise it would probably help to know what networking
equipment was involved.
Adrian McMenamin
OK .123 is RTL8139, SMC EZ Card
.1 is PCMCIA 3Com 8c589 card (badged as Ethernet III)
.2 is Dreamcast Broadband Adapter
What should I be looking for in the routing table?
.2 can see everything btw.
--
Adrian McMenamin
adr...@mcmen.demon.co.uk
Adrian McMenamin
I changed the client address to .11 and it all worked.
Is there a problem using a .1 address in these circumstances? (As by custom
it is a router address?)
--
Adrian McMenamin
adr...@mcmen.demon.co.uk
hu...@unixcook.com
Any firewall stuff involved like ipchains?
ipchains -L -n
Hubba
--
------------------------------------------------------------------------
- Hubertus Alexander Haniel ,,, http://www.unixcook.com -
- Shorne, Kent, UK (o o) ICQ UIN: 1470384 -
---------------------------oOOo--(_)--oOOo------------------------------
Simon Waters
>
> > What should I be looking for in the routing table?
Specific routes to ".1" different from the network address. Just
post "netstat -rn" output, and the ifconfig output, someone will
tell you if it is wrong.
> I changed the client address to .11 and it all worked.
>
> Is there a problem using a .1 address in these circumstances? (As by custom
> it is a router address?)
NAFAIK - what happens if you change it back to .1, making
routers one is just a convention.
Possible something else thinks it is one as well?
Alex Butcher
> My gateway machine 192.168.62.123 cannot ping 192.168.62.1 (all packets
> get lost) but if I ping 192.168.62.255 -b packets come back from
> 192.168.62.1.
>
> On the otherhand, there seems no way that I can get 192.168.62.1 to ping
> 192.168.62.123, but it can ping 192.168.62.2.
>
> What are the sorts of things I should be looking at to fix this?
Hmmm.. check your netmask settings are the same on both hosts and that
they're within the same subnet.
Best Regards,
Alex.
--
Alex Butcher Brainbench MVP for Internet Security: www.brainbench.com
Berkshire, UK Need reliable and secure network systems?
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