Bandwidth Question

amb1s1

Which show command shows the bandwidth on a router.

kafifi13

Off the top of my head i don't remeber. If i was infront of my router i'd be able to tell you. I believe it's show interface and select the interface you want to know the bandwidth of.

amb1s1

That is my problem. I'm taking the test at 12:00 and I think is sh interface, but I'm not sure. The problem is that I don't have the sim install on this pc

kafifi13

Hey...i saw you were in a dilma so i installed that Sim i have here at work just to test it out...it is Show interface. I configuired my serial interface with a bandwidth and did Show interface and came up as:

BW 64Kbit

tech-airman

amb1s1 wrote:

Which show command shows the bandwidth on a router.

amb1s1,

Unfortunately, no show command is going to show you the bandwidth for an interface if the current bandwidth is the default bandwidth.

So off the top of my head:

1. Serial = 1.544 Mbps
2. Ethernet = 10 Mbps
3. FastEthernet = 100 Mbps
4. GigabitEthernet = 1000 Mbps

larkspur

sh int

tech-airman

kafifi13 wrote:

Hey...i saw you were in a dilma so i installed that Sim i have here at work just to test it out...it is Show interface. I configuired my serial interface with a bandwidth and did Show interface and came up as:

BW 64Kbit

kafifi13,

The throughput for a serial interface by default is 1.544 Mbps. In order to configure the serial interface to operate at 64 Kbps, you would use the following configuration step...

(config-if)#clock rate 64000

However, the following configuration would not actually change the throughput for the interface but instead, make the interface either more or less "attractive" for an IGRP or EIGRP metric calculation...

(config-if)#bandwidth 64000

floppydisk

a SHOW RUN CONFIG will show the "bandwidth xxxxx" on the desire interface

tech-airman

floppydisk wrote:

a SHOW RUN CONFIG will show the "bandwidth xxxxx" on the desire interface

floppydisk,

The purpose of the "bandwidth xxxxx" command is to influence the IGRP and EIGRP metric calculation process and not to change the actual throughput of the interface.

r_durant

tech-airman wrote:

amb1s1 wrote:

Which show command shows the bandwidth on a router.

amb1s1,

Unfortunately, no show command is going to show you the bandwidth for an interface if the current bandwidth is the default bandwidth.

So off the top of my head:

1. Serial = 1.544 Mbps
2. Ethernet = 10 Mbps
3. FastEthernet = 100 Mbps
4. GigabitEthernet = 1000 Mbps

tech-airman,
Are you sure this statement is correct..."Unfortunately, no show command is going to show you the bandwidth for an interface if the current bandwidth is the default bandwidth."??

I've just checked one of our routers here at work, with the current bandwidth as the default bandwidth and I can see the the bandwidth using the "sh int s0" command...

Netstudent

http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/dial_r/drprt1/drsyncs.htm

Default
Default bandwidth values are set during startup and can be displayed with the EXEC command show interfaces.

Just in case there was any confusion there.

tech-airman

r_durant wrote:

tech-airman wrote:

amb1s1 wrote:

Which show command shows the bandwidth on a router.

amb1s1,

Unfortunately, no show command is going to show you the bandwidth for an interface if the current bandwidth is the default bandwidth.

So off the top of my head:

1. Serial = 1.544 Mbps
2. Ethernet = 10 Mbps
3. FastEthernet = 100 Mbps
4. GigabitEthernet = 1000 Mbps

tech-airman,
Are you sure this statement is correct..."Unfortunately, no show command is going to show you the bandwidth for an interface if the current bandwidth is the default bandwidth."??

I've just checked one of our routers here at work, with the current bandwidth as the default bandwidth and I can see the the bandwidth using the "sh int s0" command...

r_durant,

What was the bandwidth value that you saw?

tech-airman

Netstudent wrote:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/dial_r/drprt1/drsyncs.htm

Default
Default bandwidth values are set during startup and can be displayed with the EXEC command show interfaces.

Just in case there was any confusion there.

Netstudent,

If you read a little further down you'd see....

Cisco wrote:

---

Note This is a routing parameter only; it does not affect the physical interface.

---

In other words, "bandwidth" doesn't change the actual operational speed of the physical interface.

r_durant

tech-airman wrote:

r_durant wrote:

tech-airman wrote:

amb1s1 wrote:

Which show command shows the bandwidth on a router.

amb1s1,

Unfortunately, no show command is going to show you the bandwidth for an interface if the current bandwidth is the default bandwidth.

So off the top of my head:

1. Serial = 1.544 Mbps
2. Ethernet = 10 Mbps
3. FastEthernet = 100 Mbps
4. GigabitEthernet = 1000 Mbps

tech-airman,
Are you sure this statement is correct..."Unfortunately, no show command is going to show you the bandwidth for an interface if the current bandwidth is the default bandwidth."??

I've just checked one of our routers here at work, with the current bandwidth as the default bandwidth and I can see the the bandwidth using the "sh int s0" command...

r_durant,

What was the bandwidth value that you saw?

tech-airman,

The value i see is..."BW 1536 Kbit"

larkspur

like i said the "sh int" command.

this will tell you what speed your interface is set to.

Serial0/1/0:0 is up, line protocol is up
Hardware is GT96K Serial
Description: Connection to xxx - Full T1
Internet address is x.x.x.x/x
MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec,
reliability 255/255, txload 3/255, rxload 3/255


GigabitEthernet0/0 is up, line protocol is up
Hardware is BCM1125 Internal MAC, address is
Description: $ETH-LAN$$ETH-SW-LAUNCH$$INTF-INFO-GE 0/0$
Internet address is x.x.x.x/x
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive not set
Full-duplex, 1000Mb/s, media type is RJ45
output flow-control is XON, input flow-control is XON

now the question is will the bandwidth be set to default if you are connected via serial to an external DSU\CSU, adtran, etc.. and the circuit is provisioned at say 256 or 512k?

to guess I would say yes. But lets see????

Netstudent

tech-airman wrote:

Netstudent wrote:

http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/dial_r/drprt1/drsyncs.htm

Default
Default bandwidth values are set during startup and can be displayed with the EXEC command show interfaces.

Just in case there was any confusion there.

Netstudent,

If you read a little further down you'd see....

Cisco wrote:

---

Note This is a routing parameter only; it does not affect the physical interface.

---

In other words, "bandwidth" doesn't change the actual operational speed of the physical interface.

I never said it did. I already knew that the bandwidth value is arbitrary. I was just clearing up any confusion about being able to see the default bandwidth value using show int . I don;t know why you are stuck on that. I don't even think that was ever in question in this thread.

Pash

Where is mike when you need him????? He better damn pass that next security lab so he can spend more time on these forums answering our fumbled questions.

tech-airman is spot on correct. Clock rate decides your link speed in a standard PPP WAN link, remember on your DCE end you set the clock rate only. The ISP usally decides the clock rate, for obvious reasons. Bandwidth is used for the purposes already stated.

http://www.cisco.com/warp/public/116/ppp_back.html#config_summ - simple exp.

Cheers,

Paul Boz

tech-airman wrote:

floppydisk,

The purpose of the "bandwidth xxxxx" command is to influence the IGRP and EIGRP metric calculation process and not to change the actual throughput of the interface.

It's also the primary decider in the OSPF "cost" metric, as well as the basis for creating an IS-IS metric as well

[edit] Let me clarify. OSPF uses the default bandwidth of an interface (fa=1, etc) to compute cost. If you want to modify the cost metric you have to do so by setting the cost, not modifying the bandwidth value.

mikearama

Just to weigh in on the conversation...

I ran a sh int f1/0/1 on one of my switch stacks and got the usual output:

FastEthernet1/0/1 is up, line protocol is up (connected)
Hardware is Fast Ethernet, address is 0011.5cfc.3783 (bia 0011.5cfc.3783)
MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
reliability 255/255, txload 1/255, rxload 1/255

So the port is set to standard fast ether specs.

When I checked the port in Orion for bandwidth/throughput usage, the actual specs (in the Today's Maximums column) were:

Receive 9 Mbps at 08:27 AM
Transmit 1.05 Mbps at 09:39 AM

So while you can see the default values that are set (sh int), there's no way from within the IOS to see actual bandwidth usage.

Mike

larkspur

amb1s1 Posted: Mon Jul 02, 2007 7:55 am Post subject: Bandwidth Question

---

Which show command shows the bandwidth on a router.

I believe we may be getting away from the orginal question or maybe the question is not clear enough?

dtlokee

Bandwidth is a configured value, if that is what you're looking for the command is "show interface serial x" to see the bandwidth for interface serial x. This bandwidth value does not indicate or control the maximum speed of an interface, only the value used to calculate the metric or cost for OSPF and EIGRP.

If the question is regarding the actual link speed from a service provider that is dependant on the several factors, but the configured bandwidth value does not control the actual speed of the interface. The clock rate command controls the clock rate of the access link, but again that may not indicate the actual speed of the connection (eg frame relay where the access rate is 1.544 mb/s but the cir is only 512kb/s)

In some router models and interface types you can use the "show controllers" command to see the actual clock rate from the provder, but again that may not be the actual speed of the connection.