Hot Swapping Network Service Modules

Software Release 2.3.1

In routers and switches that have NSM bays, this release allows the following NSMs to be hot swapped, so that they can be installed and uninstalled without powering down the entire router or switch:

■AT-AR040 NSM with 4 PIC slots (NSM-4PIC)

■AT-AR041 NSM with 8 BRI S/T WAN ports (NSM-8BRI)

■AT-AR042 NSM with 4 BRI S/T WAN Ports (NSM-4BRI)

The following PIC cards can be hot swapped if they are in NSM bays:

■AT-AR021(S) PIC BRI (S)

■AT-AR021(U) PIC BRI (U)

■AT-AR022 PIC Eth

■AT-AR023 PIC Sync

■AT-AR026 PIC 10/100 Eth

PICs in PIC bays in base router units (for instance, the AR720 and AR740 routers) do not support hot swapping. The PICs in an NSM can only be hot swapped by preparing the NSM bay for hotswap.

An NSM, with or without PICs, can be hot inserted into a previously empty bay. Hot inserted cards behave as though they had been present at router start- up, except that the router configuration script will not be scanned for commands that may relate to interfaces on the hot-inserted cards.

An NSM, with or without PIC cards, can be hot swapped out, and an identical combination of NSM and PIC cards can be hot swapped into the same bay. The software configurations of the interfaces on the hot-swapped cards are preserved across the hot swap so that modules configured to interfaces on the cards can continue to use the interfaces.

An NSM, with or without PICs, can be hot swapped out and a different combination of NSM and PICs can be hot swapped into the same bay. For any card in the combination that is replaced by a card of a different type, software interface instances for the old card are destroyed and their configurations forgotten, and new interface instances are created from scratch for the new card. For any card in the combination that is replaced by a card of the same type, interface instances are preserved.

NSM-4PIC (AR040) only: Cards of the same type but with differing manufacturing revision levels may in some cases be treated as cards of different types when hot swapping.

WARNING: It is important to observe the following procedure carefully when hot swapping NSMs. Failure to follow this procedure will cause the router to crash, and may cause damage to files stored in FLASH.

Do not attempt to hot swap while the contents of FLASH memory are being modified, for instance when files are being loaded onto the router or during FLASH compaction. Hot swapping while FLASH memory is being modified may corrupt FLASH memory, damaging configuration files, software release

Software Release 2.3.1 C613-10325-00 REV B