Or we sell an LSS, LAN Switching Service, service in which you can build a trunk across the bridged ATM network.
Dave Tom Martin wrote: > Alaerte, > > I can think of a couple ways to doing this. Be forewarned. Both are ugly. > > Method #1: Relocate the servers /30 subnet > ------------------------------------------ > > We'll say the server's IP address is 192.3.3.254/24. Create a secondary > IP address on R2 for 192.3.3.252/30. R2's secondary address becomes > 192.3.3.253/30, the server can stay 192.3.3.254/24. Make sure that R3 > knows how to reach the 192.3.3.252/30 subnet (either static route or a > classless routing protocol). > > How it works: > > Proxy ARP. Stations on VLAN 300 attempting to connect to the server will > ARP for 192.3.3.254, for which R3 has a "better route", and will respond > to the ARP with its own MAC. Traffic to 192.3.3.254 will be routed to > R2. The reverse will happen when 192.3.3.254 attempts to respond to the > client, it ARPs, R2 knows of a route and responds with its MAC, the > packet is routed back. > > Other info: > > - I've assumed that the server address was 192.3.3.254, it could have > been anything. The /30 subnet would change accordingly. > - I've assumed that .252 and .253 were not already in use. If they were, > connectivity to these stations would be broken. You can get around this > problem by configuring (and redistributing) static routes for > 192.3.3.252/32 and 192.3.3.253/32 pointed back towards Vlan 300 on R3. > - L2 Broadcasts will not be available to/from the new server > > > Method #2: Virtual router > ------------------------- > > This method has the unique property of being both cleaner (from a caveat > perspective) and uglier at the same time. Imagine walking into this at a > customer site -- how long would it take you to figure out what was going > on? :) > > Once again we'll say the server's IP address is 192.3.3.254/24. > Configure a static route on R3 as follows: > > ip route 192.168.3.254 255.255.255.255 (ip_of_R2) > > On R2, determine an IP address that isn't used for use as a virtual > router. We'll say 192.168.2.254/24 isn't used. Create a static route on > R2 to the server through the virtual router: > > ip route 192.168.3.254 255.255.255.255 192.168.2.254 > > The virtual gateway doesn't exist so pings to it will fail. Don't worry > about that yet. Move the server to VLAN 200 without changing its IP > address or mask. Determine the MAC address of the server. We'll say > 0001.0002.0003. On R2, configure the MAC for the virtual router to be > the server's IP: > > arp 192.168.2.254 0001.0002.0003 arpa > > You must perform similar steps on the server. We'll assume that its > default gateway has not changed. We'll also assume that its default > gateway was 192.3.3.1. Configure a static ARP entry for the default > gateway that reflects R2's Ethernet MAC (0102.0304.0506): > > arp -s 172.30.16.254 01:02:03:04:05:06 > > Make sure that R3 knows how to reach the 192.3.3.254/32 subnet (either > add a static route or redistribute on R2). > > How it works: > > Vlan 300 stations broadcast ARP, and R3 responds with its MAC (Proxy > ARP). R3 forwards the packets to R2. R2 forwards the packets directly to > the server (although it believes it is forwarding to another gateway). > The server receives the packet because the MAC was correct, notices that > it is the end station, and processes the packet. Traffic from the server > to VLAN 300 is possible using Proxy ARP as describe in Method 1. Traffic > to/from other VLANs (VLAN 100) will also work fine since the server > forwards all of its "default gateway" traffic to the correct default > gateway, R2. > > Other info: > > - I've assumed that the server address was 192.3.3.254, it could have > been anything. > - The only 192.3.3.0/24 address used on VLAN 200 (other than the servers > IP) is the Ethernet IP address of R3. > - L2 Broadcasts will not be available to/from the new server > - Pings to the virtual router will fail (it /is/ virtual after all), > even though the server will have full network connectivity. > > > If you get around to actually doing either of these in the lab and run > into trouble, let me know (the above was written from memory, and I may > have missed a step or two). I originally came across these ideas after > reading Doyle and configured them in the lab just to see if I could pull > it off. Yep. :) > > You would be surprised with some of the crazy labs you can make for > yourself when IP addresses don't need to be contiguous or need to match > the local router! > > - Tom > > > alaerte Vidali wrote: > >>Need to transport multiple Vlans over PoS. >> >>Any Thoughts? >> >>It is a short term need. It is necessary to move a server without changing >>its IP address from Vlan 300 to Vlan 200 and a server from Vlan 100 to Vlan >>200. >> >> >>Vlan 100 (192.1.1.0) R1 ----------- R2 (192.2.2.0) Vlan 200 >> | | >> | | >>Vlan 300 (192.3.3.0) R3--------------- -- David Madland CCIE# 2016 Sr. Network Engineer Qwest Communications 612-664-3367 "Government can do something for the people only in proportion as it can do something to the people." -- Thomas Jefferson Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=71165&t=71074 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
