intervlan routing and policy routing C3750 or C 4948


Hi,

I'm testing before I buy it cisco 3750G.(i'm thinking about 4948 to )

I want use this switch as L3 router for my network.

I want to keep intervlan routing on the switch (about 50 vlans with L3 routing) and for some vlans i need different gateways.

I tried to run policy  routing on incoming vlan

interface Vlan10
ip address 10.10.10.1 255.255.255.128
ip policy route-map test

interface Vlan11
ip address 10.10.10.129 255.255.255.128


interface Vlan100
ip address 200.200.200.1 255.255.255.252


access-list 1300 permit 10.10.10.0 0.0.0.127
route-map test permit 1300
match ip address 1300
set ip next-hop 200.200.200.2


in this scenerio all packets from vlan 10 are policy routed to 200.200.200.2. even traffic to vlan11.

I want policy routing for packets that aren't in local routing table.

I found on newsgroups
"
If you use "set ip next-hop" or "set interface," the precedence is: 1)
route-map, 2) routing table.  So if the interface specified in the
route-map is up, or if the next-hop specified in the route-map appears
in the routing table, then the packets will be routed according to the
route-map set statement.  If, on the other hand the next-hop is not in
the routing table/interface is down, then the policy will be ignored and
the packet will be routed according to the routing table (standard IOS
routing).
If you instead use "set ip default next-hop" or "set default interface,"
the behavior is exact opposite.  In this case, the precedence is: 1)
routing table, 2) route-map.  So if the destination matches anything in
the routing table (including a default route), the route-map will never
be used.  If there is no match in the routing table for the dest IP,
then the route-map will be used to forward the packet (assuming the
specified next-hop appears in the routing table/specified interface is up).
"

but set ip default next-hop isn't CEF or Fastswitching operation for 3750G or 4948

for C 4500 ( I Think it will applay to 4948 - which is based on C4500)
 I found this:


The Catalyst 4500 switching engine supports matching a "set next-hop" route-map action with a packet on a permit ACL. All other route-map actions, as well as matches of deny ACLs, are supported by a flow switching model. In this model, the first packet on a flow that matches a route-map will be delivered to the software for forwarding. Software determines the correct destination for the packet and installs an entry into the TCAM so that future packets on that flow are switched in hardware. The Catalyst 4500 switching engine supports a maximum of 4096 flows


for C 3750 I found this:

IP PBR can now be fast-switched. Prior to Cisco IOS Release 12.0, PBR
could only be process-switched, which meant that on most platforms the
switching rate was approximately 1000 to 10,000 packets per second. This
speed was not fast enough for many applications. Users who need PBR to
occur at faster speeds can now implement PBR without slowing down the
router.

Fast-switched PBR supports all of the match commands and most of the set
commands, with the following restrictions:

   * The set ip default next-hop and set default interface commands are
not supported.
   * The set interface command is supported only over point-to-point
links, unless a route-cache entry exists using the same interface
specified in the set interface command in the route map. Also, at the
process level, the routing table is consulted to determine if the
interface is on a reasonable path to the destination. During fast
switching, the software does not make this check. Instead, if the packet
matches, the software blindly forwards the packet to the specified
interface.



-------------

There is posibility to use intervlan routing and pbr for vlans to route outside local routing table via separate gateways (no default gateway) and do it in hardware ?

Switch C3750G or C4948.

Thanks a lot for any good informations

siedar
.

Relevant Pages

  • Re: NAT implementation in an IM driver
    ... and then deliver the packet to the IP stack. ... The IP routing from TCP/IP ... Internet providers) Windows will route the packet only on one interface, ...
    (microsoft.public.development.device.drivers)
  • Re: [2.4 PATCH] bugfix: ARP respond on all devices
    ... > interface with a foreign IP as source, ... When we're routing, we'll use an interface address of ... the source address in the outgoing packet is local to ... send the line "unsubscribe linux-kernel" in ...
    (Linux-Kernel)
  • Re: Stack virtualization (was: running out of mbufs?)
    ... > interface lists after all, just as you stated yourself at the beginning ... I thinking more along the lines of OpenBSD's interface groups. ... For example I want to have multiple routing tables within the same ... An incoming packet on interface em0 with group priority ...
    (freebsd-net)
  • Re: The priority of routing table in Windows?
    ... Maxim Shatskih, Windows DDK MVP ... > tcpip.sys choose the interface to send packet if the destination IP is ... For example, the routing table is: ... > interface, such as 192.168.1.101, even through I reset other interfaces. ...
    (microsoft.public.development.device.drivers)
  • Re: Traffic NOT moving through the correct network interface?
    ... Kernel IP routing table ... loopback interface, but that's not part of this problem. ... Everything is done by the kernel. ... Policy based routing requires you ...
    (alt.os.linux)