Nortel Networks NN47200-503 manual Brouter port, Proxy ARP UDP broadcast

IP routing 19

If secondary interfaces are configured on the management VLAN, routing cannot be disabled globally or on the management VLAN. Secondary IP interfaces on the management VLAN are purged from NVRAM when

•a unit leaves the stack and the switch does not have a manually configured IP

•the switch fails to get the IP address through the BootP mode

The following are not supported on secondary interfaces:

•DHCRP

•Proxy ARP

•UDP broadcast

•IPFIX

•VRRP, OSPF, RIP

For information about configuring secondary interfaces on VLANs, see "IP routing using VLANs" (page 16).

Brouter port

The Nortel Ethernet Routing Switch 5500 Series supports the concept of brouter ports. A brouter port is a single-port VLAN that can route IP packets as well as bridge all non-routable traffic. The difference between a brouter port and a standard IP protocol-based VLAN configured to do routing is that the routing interface of the brouter port is not subject to the spanning tree state of the port. A brouter port can be in the blocking state for non-routable traffic and still be able to route IP traffic. This feature removes any interruptions caused by Spanning Tree Protocol recalculations in routed traffic. A brouter port is actually a one-port VLAN; therefore, each brouter port decreases the number of available VLANs by one and uses one VLAN ID.

When a brouter port is created, the following actions are also taking place on the switch:

•A port-based VLAN is created.

•The brouter port is added to the new port-based VLAN.

•The PVID of the brouter port is changed to the VLAN ID of the new VLAN.

•The STP participation of the brouter port is disabled.

•An IP address is assigned to the brouter VLAN.

Nortel Ethernet Routing Switch 5500 Series

Configuration-IP Routing Protocols

NN47200-503 03.01 Standard

5.127 August 2007

Copyright © 2005-2007, Nortel Networks