When I started with my CCIE Journey, I had some 2511 to make sure I had remote console access. For my current lab I had to configure a NM-16A in an ISR router. How to set it up? Of course there is good documentation to Configure a Terminal but not everything was in that post.
NM-16A
The NM-16A is an async module for an ISR with 16 connections. First of all, let’s check if there is a NM-16A module in the router with the following command:
show hw-module all attribute
Slot 0 Bay 1 Board 0 Module[NIM-16A] spa_type 0xD1F Daughter Board Not Present
Base mac_addr 084f.f9a7.080c mac_blk_sz 4 Endpt MAC Address offset(s) : 0
Basic attributes : length 12, version [3], module-type [ngio], width [Single Wide]
Power Rating [20], Control Endpoint count [1], Daughter Board Count [0]
KR Support [0x00], 16-bit GPIO [Not present], Submodule reset support [Not required]
Extended Attributes for [16 ports Async Serial NIM]
GPIO Pin Information
Input Pin[Daughter board presence]
Output Pin[Boot select]
Input Pin[PRI interface ready]
I2C Information
[dev_addr 0xA dev_type clock]
Port type async serial Range [0 15] Per-port Information : Max IID [1] Connector [rs232] Network clocking [disable]
Module OID: 1 3 6 1 4 1 9 12 3 1 9 105 31
Port OID: 1 3 6 1 4 1 9 12 3 1 10 8
This was just a snippet.
NM-16A Configuration
The following configuration is working for me. I like to have a password on the lines.
line 0/1/0 0/1/15
session-timeout 20
exec-timeout 0 0
password Cisco123!
logging synchronous
login
no exec
transport input all
transport output none
To configure a name to connect to a console port, you must know the line numbers. Here you see all the lines of the ISR:
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To connect to line 0/1/0 you see the number 2 as line number. You can connect to the loopback address of the router on port 2000 + line number. In this case it will be 2002.
ip host asa 2002 1.1.1.1
no ip domain lookup
The ip address 1.1.1.1 is the loopback 0 interface of the router.
Connect to another router via the async line.
To open a console connection to the ASA, I easily can type ASA and it will connect to loopback address on port 2002.
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During the session on the ASA, when you hit CTRL+SHIFT+6 / X you will return to the router and the session is still open.

Whit show sessions you see the sessions that are open and you can switch between them.
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To reset the line, you can disconnect the correct line number.
ISR4300_Console#disconnect 1 Closing connection to asa [confirm]
To verify all connections are closed:
ISR4300_Console#sh sessions % No connections open ISR4300_Console#