initial-tcp-mss
Syntax
initial-tcp-mss mss-value;
Hierarchy Level
[edit security policies from-zonezone-name
to-zonezone-name
policypolicy-name
then permit tcp-options]
Description
Configure the TCP maximum segment size (MSS) for packets that arrive at the ingress interface (initial direction), match a specific policy, and for which a session is created. The value you configure overrides the TCP MSS value in the incoming packet when the value in the packet is higher than the one you specify.
The initial-tcp-mss
value per policy takes precedence
over a global tcp-mss
value (all-tcp
, ipsec-vpn
, gre-in
, gre-out
), if one is
configured. However, when the syn-flood-protection-mode syn-proxy
statement at the [edit security flow]
hierarchy level
is used to enable SYN proxy defenses against SYN attacks, the TCP
MSS value is not overriden.
Because each policy has two directions, you can configure a
value for both directions or for just one direction. To configure
a TCP MSS value for the reverse session, use the reverse-tcp-mss
option.
Required Privilege Level
security—To view this statement in the configuration.
security-control—To add this statement to the configuration.
Release Information
Statement introduced in Junos OS Release 12.3X48-D20.