TTL Normalization

TTL normalization pertains to both IP4 TTL (time-to-live) and IP6 (hop limit) and is only performed if both the relevant base normalization is enabled (as described above) and the minimum and new TTL values are configured, as follows:

    config min_ttl: <min_ttl>
    config new_ttl: <new_ttl>

    <min_ttl> ::= (1..255)
    <new_ttl> ::= (<min_ttl>+1..255)

If new_ttl $>$ min_ttl, then if a packet is received with a TTL $<$ min_ttl, the TTL will be set to new_ttl.

Note that this configuration item was deprecated in 2.8.6:

    preprocessor stream5_tcp: min_ttl <#>

By default min_ttl = 1 (TTL normalization is disabled). When TTL normalization is turned on the new_ttl is set to 5 by default.