Cisco CISCO2650 - 2650 Router Hardware Installation Manual page 110

Asynchronous Network Module Interface Numbering
Port Interface Numbering
The Cisco MWR 1941-DC router requires Cisco IOS Release 12.2(15)MC1a and later for 4- and 8-port
Note
asynchronous/synchronous and 16- and 32-port asynchronous modules network module support.
4- and 8-Port
The 4-port and 8-port asynchronous/synchronous network modules, when configured for asynchronous
operation under releases earlier than Cisco IOS Release 11.2(7)P, use a different interface numbering
algorithm:
interface-number = (16 x slot-number) + unit-number + 1
16- and 32-Port
Table 5-5
potential conflicts with the numbers assigned to 16- and 32-port asynchronous modules; that is, it would
be possible for a 16- or 32-port asynchronous module in one slot to overlap the interface numbers of a
4- or 8-port asynchronous and synchronous module in another slot.
Table 5-5
Slot Number
0
1
1
2
1
3
4
5
1. Cisco 3640 and Cisco 3660 routers only.
To prevent this conflict, Cisco IOS Release 11.2(7)P, which is required to operate 16- and 32-port
asynchronous network modules, checks when the router boots for the presence of 4- and 8-port
asynchronous/synchronous network modules configured as asynchronous. If the software finds any of
these network modules, it rewrites the starting configuration in nonvolatile random access memory
(NVRAM), if necessary, to adopt the new line numbering scheme for these modules, as shown in
Table 5-6 on page
Table 5-6
Slot Number
0
1
Cisco Network Modules Hardware Installation Guide
5-8
shows the numbers available under this numbering scheme. These interface numbers create
4-, 8-, and 16-Port Serial Network Module Interface Numbering
Interface Numbers
(4-Port Module)
1–4
17–20
33–36
49–52
N/A
N/A
5-8.
New 4- and 8-Port Serial Network Module Interface Numbering
Interface Numbers (4-Port
Module)
1–4
33–36
Chapter 5
Interface Numbers Interface Numbers
(8-Port Module) (16-Port Module)
1–8 1–16
17–24 17–24
33–40 33–40
49–56 49–64
N/A 65–80
N/A 81–96
Interface Numbers (8-Port
Module)
1–8
33–40
Connecting Serial Network Modules
OL-2485-20