11-11-2012 08:23 AM - edited 03-04-2019 06:06 PM
Hi,
The physical Gigabit interface in this router has bandwidth command set & the show interface command output reflects the same
But how does the Subinterface get its bandwidth set to 100 Mbps? I always thought subinterfaces inherit the physical interface bandwidth. isnt it?
Router#sh int GigabitEthernet0/0
GigabitEthernet0/0 is up, line protocol is up
Hardware is BCM1125 Internal MAC, address is 64ae.0c98.ba10 (bia 64ae.0c98.ba10)
Description: link to PE
MTU 1500 bytes, BW 10000 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 4/255, rxload 33/255
Encapsulation 802.1Q Virtual LAN, Vlan ID 1., loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s, media type is RJ45
output flow-control is XON, input flow-control is XON
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:00, output 00:00:00, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 111823
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 1323000 bits/sec, 142 packets/sec
5 minute output rate 177000 bits/sec, 96 packets/sec
3331038420 packets input, 405011219 bytes, 0 no buffer
Received 11024 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
2480626113 packets output, 2746510267 bytes, 0 underruns
1 output errors, 0 collisions, 3 interface resets
0 unknown protocol drops
0 babbles, 0 late collision, 0 deferred
1 lost carrier, 0 no carrier, 0 pause output
0 output buffer failures, 0 output buffers swapped out
Router#sh run int GigabitEthernet0/0
Building configuration...
Current configuration : 186 bytes
!
interface GigabitEthernet0/0
description link to PE
bandwidth 10000
no ip address
ip flow ingress
ip route-cache flow
duplex full
speed 100
media-type rj45
no cdp enable
end
Router#sh int GigabitEthernet0/0.2015
GigabitEthernet0/0.2015 is up, line protocol is up
Hardware is BCM1125 Internal MAC, address is 64ae.0c98.ba10 (bia 64ae.0c98.ba10)
Internet address is x.x.x.x/30
MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
reliability 255/255, txload 4/255, rxload 32/255
Encapsulation 802.1Q Virtual LAN, Vlan ID 2015.
ARP type: ARPA, ARP Timeout 04:00:00
Last clearing of "show interface" counters never
Router#sh run int GigabitEthernet0/0.2015
Building configuration...
Current configuration : 174 bytes
!
interface GigabitEthernet0/0.2015
encapsulation dot1Q 2015
ip address x.x.x.x 255.255.255.252
no cdp enable
service-policy output SE_SNAP_Q9000K_1M-0-7M-0_25
end
Solved! Go to Solution.
11-11-2012 04:09 PM
Pradeep H A
Please see this link
http://www.cisco.com/en/US/docs/ios/12_3/interface/command/reference/int_a1g.html#wp1184839
This explains what happens with bandwidth on interfaces and sub interfaces
Regards,
Alex.
Please rate useful posts.
11-11-2012 08:31 AM
Hi,
Bandwidth command under interface configuration is used by dynamic routing protocol such as EIGRP to calculate metric.
It does not affect to real bandwidth of interface.
Regards Abzal
Please rate helpful posts.
Sent from Cisco Technical Support iPhone App
11-11-2012 04:09 PM
Pradeep H A
Please see this link
http://www.cisco.com/en/US/docs/ios/12_3/interface/command/reference/int_a1g.html#wp1184839
This explains what happens with bandwidth on interfaces and sub interfaces
Regards,
Alex.
Please rate useful posts.
06-23-2015 05:00 AM
It is very important to define the Bandwidth statement if the access speed is different to the interface speed.
Capacity planning with gather uilisation against the bandwidth, so if it is wrong, you could get false positives, or worse, false negatives for utilisation.
Always good practice to code Bandwidth in any case (except where variable, e.g. DSL).
02-28-2018 12:03 PM
@STEVE CLARK wrote:
It is very important to define the Bandwidth statement if the access speed is different to the interface speed.
Capacity planning with gather uilisation against the bandwidth, so if it is wrong, you could get false positives, or worse, false negatives for utilisation.
Always good practice to code Bandwidth in any case (except where variable, e.g. DSL).
So are you saying if you interface speed is 1 Gig to use bandwidth to set it to 1 00mg?
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