Configuring the ATM SPAs
Command or Action
Step 3
Router(config-if)# ip mtu bytes
Example:
Step 4
Router(config-if)# mpls mtu bytes
Example:
Step 5
Router(config-if)# end
Example:
Verifying the MTU Size
To verify the MTU sizes for an interface, use the show interfaces, show ip interface, and show mpls interface
commands, as in the following examples:
The output of the show interfaces atm command can display configuration of AAL5 encapsulation, but
Note
only AAL0 is supported on the Cisco ASR 1000 Series Aggregation Services Routers.
Router# show interfaces atm 0/2/2
ATM0/2/2 is up, line protocol is up
Hardware is SPA-3XOC3-ATM-V2, address is 001a.3044.7522 (bia 001a.3044.7522)
MTU 4470 bytes, sub MTU 4470, BW 149760 Kbit, DLY 80 usec,
Encapsulation ATM, loopback not set
Keepalive not supported
Encapsulation(s): AAL5 AAL0
4095 maximum active VCs, 1 current VCCs
VC Auto Creation Disabled.
VC idle disconnect time: 300 seconds
4 carrier transitions
Last input never, output 00:04:11, output hang never
Last clearing of "show interface" counters never
Input queue: 0/375/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
Router# show ip interface atm 0/2/2.1
ATM0/2/2.1 is up, line protocol is up
Internet address is 10.4.0.2/24
Broadcast address is 255.255.255.255
OL-14127-17
Purpose
(Optional) Configures the MTU value, in bytes, for IP packets on this interface.
The valid range for an ATM SPA is 64 to 9288, with a default value equal to the
MTU value configured in Step 2.
(Optional) Configures the MTU value, in bytes, for MPLS-labeled packets on
this interface. The valid range for an ATM SPA is 64 to 9216 bytes, with a default
value equal to the MTU value configured in Step 2.
Exits interface configuration mode and returns to privileged EXEC mode.
reliability 255/255, txload 1/255, rxload 1/255
5 packets input, 540 bytes, 0 no buffer
Received 0 broadcasts (0 IP multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
5 packets output, 540 bytes, 0 underruns
0 output errors, 0 collisions, 1 interface resets
0 output buffer failures, 0 output buffers swapped out
Cisco ASR 1000 Series Aggregation Services Routers SIP and SPA Software Configuration Guide, Cisco IOS XE
Modifying the Interface MTU Size
Everest 16.5
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