Router Alert Ip Option - Nokia IPSO 4.0 Reference Manual

Only the remote terminating node responds to the MSS value you set; that is, intermediate
nodes do not respond. Generally, however, intermediate notes can handle 1500-byte MTUs.
Your system advertises the MSS value you set, and remote terminated nodes respond by sending
segments in packets that do not exceed your advertised value. This segment size your system
advertises should be 40 bytes less than the smallest MTU between your system and the outgoing
interface. The 40-byte difference allows for a 20-byte TCP header and a 20-byte IP header,
which are included in the MTU.
To set the TCP MSS
1. Click Advanced System Tuning under Configuration > System Configuration in the tree
view.
2. Click the Advanced System Tuning link in the System Configuration section.
3. Enter the value you will use for your MSS.
The range for this value is 512 through 1500, and the default value is 1024. If you enter a
value outside of this range, an out-of-range error is generated.
4. Click Apply.
5. Click Save to make your changes permanent.

Router Alert IP Option

You can use this feature to specify whether IPSO should strip the router alert IP option before
passing packets to the firewall. (The router alert IP option is commonly enabled in IGMP
packets.)
Nokia Network Voyager for IPSO 4.0 Reference Guide 181