You have a point, what if I increase MTP size to 9000 on that point to point interface?
-- Sent from my iPhone > On Jun 21, 2016, at 1:10 AM, Mike <[email protected]> > wrote: > >> On 06/20/2016 07:52 PM, Satish Patel wrote: >> This is weird question but i thought let me get opinion from you guys. >> We have following scenario >> >> [ISP]------<Public-IP>-----[Router]-------<Private-IP>-------[L3 >> Switch]------------[Hosts] >> >> >> In above diagram we get /24 subnet from ISP for hosts, Now i want to >> configure routed network between [Router] and [L3 switch] so can i use >> Private IP address (rfc1981) like 192.168.100.1/30 instead of Public >> IP address, to save public IP address in point to point link. what >> would be the disadvantage i will get doing that? > > > Well, if I understand your question, you want to put private IP's on the > point-to-points to save ip addresses. The only primary side-effect you will > have is for path mtu discovery - if the router or l3 switch needs to fragment > a packet for example (or send back any other icmp messages like host > unreachable or the like), it's likely to use the interface address 'facing' > the destination which would be your private IP's. These are dropped by many > firewalls and such, which effectively breaks path mtu discovery and such. > Depending on your equipment, you could assign 1 public IP to a loopback > interface on the router and to the l3 switch, which usually will cause that > device to use that address as the source for any icmp messages it generates.I > am not %100 certain of the fine details (would love someone to point out an > authoratitive doc that explains this for cisco), but I have used this method > for exactly this reason and it does seem to work. > > Mike- > > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
