Configuring the Optional Checksum

The optional checksum encapsulates optional checksum Type-Length-Values (TLVs) into SNPs and Hello packets. After an IS-IS device receives the packets, it checks whether the checksum TLVs are correct, which improves network security.

Context

The optional checksum encapsulates optional checksum TLVs into the Complete Sequence Numbers Protocol Data Units (CSNPs), Partial Sequence Number Protocol Data Units (PSNPs), and Hello packets sent by IS-IS devices. When the peer device receives the encapsulated packets, it checks whether TLVs carried in the packets are correct. If TLVs are not correct, the peer device discards the packets for network security.

Procedure

  1. Run system-view

    The system view is displayed.

  2. Run isis

    An IS-IS process is created, and the IS-IS view is displayed.

  3. Run optional-checksum enable

    IS-IS optional checksum is enabled.

    If MD5 authentication or Keychain authentication with valid MD5 authentication is configured on an IS-IS interface or area, IS-IS devices send Hello packets and SNP packets without checksum TLVs but verify the checksum of received packets.

  4. Run commit

    The configuration is committed.

Parent Topic: Improving IS-IS Network Security
Copyright © Huawei Technologies Co., Ltd.
Copyright © Huawei Technologies Co., Ltd.
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