Specify the mtu size, Disable checksums, Disable fast switching through the cache – AIS Router AI2524 User Manual

Page 212

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AI2524 Router Card User’s Manual

Page 9-54

August 1997

2524UM

Specify the MTU Size

All interfaces have a default maximum packet size. However to reduc
fragmentation, you can set the MTU size of the packets sent on the in-
terface. The minimum value is 512; the default and maximum packet
size depends on the interface type.

Changing the MTU value with the

mtu

interface configuration com-

mand can affect the CLNS MTU value. If the CLNS MTU is at its
maximum given the interface MTU, the CLNS MTU will change with
the interface MTU. However, the reverse is not true; changing th
CLNS MTU value has no effect on the value for the

mtu

interface con-

figuration command.

In interface configuration mode, set the CLNS MTU packet size for a
specified interface:

clns mtu

size

Warning: The CTR card does not support the switching of frames

larger than 4472 bytes. Interoperability problems might
occur if CTR cards are intermixed with other Token Ring
cards on the same network. These problems can be mini
mized by lowering the CLNS MTU sizes to be the same on
all routers on the network.

Disable Checksums

When the ISO CLNS routing software originates a CLNS packet, by
default it generates checksums. In interface configuration mode, dis-
able checksum generation:

no clns checksum

Warning: Enabling checksum generation has no effect on routing

packets (ES-IS, ISO IGRP, and IS-IS) originated by th
router; it applies to pings and traceroute packets.

Disable Fast Switching Through the Cache

Fast switching through the cache is enabled by default for all sup-
ported interfaces. In interface configuration mode, disable fast switch-
ing:

no clns route-cache

Warning: The cache still exists and is used after the

no clns

route-cache

interface configuration command is

used; the software just does not do fast switching through
the cache.

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