Lucent Technologies 6000 - Manual (Page 372)

9-8 MAX 6000/3000 Network Configuration Guide
Configuring IP Routing
Configuring LAN interfaces
Configuring routing table updates
By setting the Ethernet > Mod Config > Ether Options > RIP parameter, you can configure
each IP interface to send RIP updates (inform other local routers of its routes), receive RIP
updates (learn about networks that can be reached through other routers on the Ethernet), or
both.
Note: Lucent recommends that you run RIP version 2 (RIP-v2) if possible. You should not
run RIP-v2 and RIP-v1 on the same network in such a way that the routers receive each other’s
advertisements. RIP-v1 does not propagate subnet mask information. It assumes the
default-class network mask. RIP-v2 handles subnet masks explicitly. Running the two versions
on the same network can result in RIP-v1 class subnet mask assumptions overriding accurate
subnet information obtained through RIP-v2.
You can set the Ethernet > Mod Config > Ether Options > Ignore Def Rt parameter to
configure the MAX unit to ignore default routes advertised by routing protocols. When you
configure the unit to ignore the default route, RIP updates do not modify the MAX routing
table’s default routes, which are static routes to other IP routers.
Configuring Address Resolution Protocol (ARP) responses
You can configure a MAX unit to respond to an ARP request with its own MAC address.
Typically, you use the Ethernet > Mod Config > Ether Options > Proxy Mode parameter to
enable Proxy ARP when the unit supplies IP addresses dynamically to dial-in users and both of
the following conditions exist:
• The MAX-supplied IP addresses are in the same local subnet as the MAX.
• Hosts on the local subnet must send packets to the dial-in clients.
Normally, you should not need to enable Proxy ARP, because most routing protocols
(including those used over the Internet) are designed to propagate subnet mask information.
A MAX unit also supports Inverse Address Resolution Protocol (Inverse ARP). Inverse ARP
enables the unit to resolve the protocol address of another device when the hardware address is
known. The unit does not issue any Inverse ARP requests, but it does respond to Inverse ARP
requests that have the protocol type of IP (8000 hexadecimal), or in which the hardware
address type is the two-byte Q.922 address (Frame Relay). All other types are discarded. The
Inverse ARP response packet sent by the unit includes the following information:
• ARP source-protocol address (the MAX unit’s IP address on the Ethernet network)
• ARP source-hardware address (the Q.922 address of the local DLCI)
(For the details about Inverse ARP, see RFCs 1293 and 1490.)
Example of configuration of a MAX IP interface on a subnet
On a large corporate backbone, many sites configure subnets to increase the network address
space, segment a complex network, and control routing in the local environment. For example,
Figure 9-6 shows the main backbone IP network (10.0.0.0) supporting a Lucent GRF router
(10.0.0.17).