Two ISP connections

[Don Bowman]

From: Andrea Venturoli [mailto:ml.ventu at flashnet.it]
> ** Reply to note from Barney Wolff <barney at databus.com> Wed, 
> 10 Dec 2003 11:39:00 -0500
> 
> 
> > I don't know of anything published that does this, but it's easy to 
> > write a perl or shell script that pings the router at the adsl isp 
> > and does the necessary things when it disappears and reappears.
> 
> Mmh, only problem is one of the ISP is famous for blocking 
> ICMP as a whole, so no pings work. I haven't tried this
> particular line yet, but I may need to use come other protocol.
> 
> 

see the lft port (layer 4 traceroute) http://www.mainnerve.com/lft/

you can use this to get an ICMP response (albeit not echo)
from your isp this way. [you can't really block icmp would
fragment, it would break PMTU].

--don