3Com C36460T, 86-0621-000 software manual Notation

Routing Protocols and Services Notes 57

CPU Utilization with XNS When the PathBuilder S5xx switch is configured for 2048 tunnels and XNS Protocol protocol, very high CPU utilization will occur.

IPX to Non-IPXA mechanism does not exist to prevent adding a path from a non-IPX routing port Configuration Error to an IPX routing port. If this situation occurs, the router stops routing IPX traffic, even though the primary port has been up the whole time. To restart IPX routing,

re-enable the port.

IPX Routing, Route When you route IPX over a Frame Relay meshed topology and configure the SAP Receive and Route Route Receive and Route Advertisement policies on the Frame Relay port, these

Advertisement Policies policies do not take effect until the SAP table is flushed.

Managing IP Address When assigning IP address to virtual ports of directly connected networks, it is Assignment important to ensure that the assigned address is valid. As LCP supports multiple

Network Control Protocols (NCPs), IP does not verify that the address is valid before bringing the port state up or down, as there may be other protocols which are utilizing that port. It is possible to have an UP port state, yet have a lack of IP connectivity.

NAT Service - Many to NAT Many to One Outbound does not translate properly when multiple addresses, One Outbound on LHS, are specified using comma (,) notation. But NAT Many to One Outbound Translation translates properly when multiple addresses, on LHS, are specified in 10.3.1.0/24

notation.

NAT Service - TCP/UDP When the NETBuilder bridge/router is configured to use TCP/UDP Port Mapping Port Mappings from port 23 (Telnet) to any other port number, the first command executed over

the session will fail due to extra characters inserted into the command string. All subsequent commands issued for that session will succeed. If you encounter this problem, execute the command again.

OSPF Route If your network is expecting more than 4000 OSPF routes you need to set the Advertisement ospfholdtime variable to 30.

PIM-Sparse Mode In Release 11.4, PIM-SparseMode does not look into the BGP routing table for RPF (reverse path forwarding) lookups. RPF lookups for IP addresses reachable only via BGP will result in RPF failures.

This has the following implications.

■A PIM-SM router will drop multicast data packets sent from a source reachable only via BGP.

■PIM-SM Rendezvous Points which are reachable only via BGP will not get added to the local RendezvousPoint set (the set of routers capable of functioning as PIM-SM RPs).

PIM-SMCisco IOS currently forwards the boot strap router (BSR) message packets without Enterprise OS/Cisco modifying the source IP address field. This implementation is incompatible with

Incompatibility 3Com Enterprise OS and there is no workaround when a PIM-SM domain contains both Cisco IOS and 3Com Enterprise OS devices.

PIM-SM Register Cisco IOS currently sends register packets with register checksum on the entire IP Checksum Formats payload, and IOS rendezvous points (RPs) also expect register checksums done on

the entire IP payload. However, 3Com Enterprise OS devices generate register