I would like to add and ask in the same sentence. The HOW-TO's (NET3 and ETH) say that including a netmask is unnecissary since the system will put the correct netmask inplace for you.
Jens, you seem to be somewhat the guru in this area. What is the scoop on that? Is it one of those things that should be but you're better off putting it in yourself to be sure? Or is it only certain situations? On Mon, 28 Apr 1997, Jens B. Jorgensen wrote: > Paul van Berlo wrote: > > > > Heya.. > > > > I finally got my ISDN running.. but now I'm experiencing some strange > > ifconfig output, something like this: > > > > ippp0 Link encap:Point-Point Protocol > > inet addr:194.109.15.56 P-t-P:194.109.31.5 > > Mask:255.255.255.255 > > UP POINTOPOINT RUNNING NOARP MTU:1500 Metric:1 > > RX packets:0 errors:74 dropped:0 overruns:0 > > TX packets:0 errors:0 dropped:83 overruns:0 > > > > RX shows 74 errors and TX shows 83 dropped packets.. This can't be right, > > since I succesfully logged on a telnet account during that session.. I'm > > using kernel release 2.1.29.. I'm also experiencing another problem.. I > > rewrote the isdn script and added a line that reads: > > route add default netmask 255.255.255.0 dev ippp0 > > Since 2.1.29 needs a netmask with the route command.. After doing this I'm > > getting name lookup errors when trying to telnet or ftp or whatever. I > > cant connect to anything. When I remove the 'netmask 255.255.255.0 dev > > ippp0' and change it to 'route add default ippp0' it works fine.. Maybe my > > netmask is wrong but I doubt it.. > > > > Any help on solving these 2 'problems' is welcomed (and I doubt its a big > > problem.. maybe I just overlooked something...) > > > > -Paul van Berlo > > > > Yes, your netmask is wrong. For a default route it should be 0.0.0.0 > since a default route is supposed to match *any* IP address. That is, > the routing algorithm compares the destination IP address of an IP > packet with each route, testing for a match by checking if: > > (dest-IP & netmask) == (route & netmask) > > More than one route may match in which case the route with the most > netmask bits wins. Note that if netmask is 0.0.0.0 each side of the > above equation will be zero no matter what the dest-IP and route > are. This is why they call it a "default" route. > > -- > Jens B. Jorgensen > [EMAIL PROTECTED] > > > -- > TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word "unsubscribe" to > [EMAIL PROTECTED] . > Trouble? e-mail to [EMAIL PROTECTED] . > > --Rick [EMAIL PROTECTED] -- TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word "unsubscribe" to [EMAIL PROTECTED] . Trouble? e-mail to [EMAIL PROTECTED] .
