Excluding connection from specific MAC address

Hi people,
I have a problem connecting from home to a Linux box at a company I do
some work for. They have a hosted solution with two machines one "live"
and one "dev". Suddenly the other night I couldn't connect or ping to
the live machine. I could connect to the dev machine, and from there ssh
on the live machine.

I really don't know what the problem is. I've spoken to my ISP who say
I don't have any blocks on my account. I have reconnected to my ISP so I
now have a different IP address, so I am not being excluded based on that.

A traceroute to the live machine fails at the hop from the firebrick to
the live machine. The hop from the firebrick to the dev machine is working.

Therefore I figure there are two possible causes.

1) The firebrick has blocked my MAC address from connecting to the live
machine.

2) The live machine is blocking any connections from my MAC address.

With regards to cause 2, how would you do this? On Linux can you block
knowledge of your existence to a machine connecting from a specific MAC
address? I have admin rights on the live machine so can change things if
required.

Thanks in advance
Jimbo

In comp.os.linux.networking Jimbo <(E-Mail Removed)>:
> Hi people,
> I have a problem connecting from home to a Linux box at a company I do
> some work for. They have a hosted solution with two machines one "live"
> and one "dev". Suddenly the other night I couldn't connect or ping to
> the live machine. I could connect to the dev machine, and from there ssh
> on the live machine.

[..]

> 1) The firebrick has blocked my MAC address from connecting to the live
> machine.

> 2) The live machine is blocking any connections from my MAC address.

Not quite, both the live machine nor its firewall will know
anything about your MAC, it's not known outside your lan.

You can check for firewall ('iptables -L') rules and
/etc/hosts.{allow|deny} on the live box, perhaps you have some
user account on another box in this subnet, you could login and
ssh back to your box, if this works, ask the guys in charge for
the firewall in front of your box, for any recent rule changes,
blocking ssh connections from the internet. This would be my
guess for the problem, if nothing changed on your box.

[..]

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