RE: full duplex or half duplex, how can you tell [7:57431]
John, It will be half duplex unless it has been configured for full duplex. Setting an ethernet interface to full duplex is done in software and requires a recent IOS. I have forgotten the minimum rev required but I know 12.2.3 will work. Dave Swink -Original Message- From: [EMAIL PROTECTED] [mailto:nobody@;groupstudy.com]On Behalf Of John Tafasi Sent: Thursday, November 14, 2002 4:57 AM To: [EMAIL PROTECTED] Subject: full duplex or half duplex, how can you tell [7:57431] Hi, I have a cisco 2516 router with an ethernet interface. How can I find out if this inteface is full duplex or half duplex? Thanks Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=57433&t=57431 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: full duplex or half duplex, how can you tell [7:57431]
John, Cisco's 25xx series uses the AMD Lance Chip for their 10Mbit Ethernet Interface. This Chipset does not support full-duplex at all. Router#show controllers ethernet 0 LANCE unit 0, ^ Have never used a 2516 myself but as far as i know it has a simple 10Mbit Ethernet Hub built in. FullDuplex Operation would require a switch. Regards Reinhold On Thu, Nov 14, 2002 at 10:56:50AM +, John Tafasi wrote: > Hi, > > I have a cisco 2516 router with an ethernet interface. How can I find out if > this inteface is full duplex or half duplex? > > > Thanks Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=57443&t=57431 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: full duplex or half duplex, how can you tell [7:57431]
""John Tafasi"" wrote in message news:200211141056.KAA04663@;groupstudy.com... > Hi, > > I have a cisco 2516 router with an ethernet interface. How can I find out if > this inteface is full duplex or half duplex? plug it into a full duplex 100 mbs switch port and see if link occurs? seriously, I believe all routers in the 25xx line are 10/half. there is no report on speed and duplex on routers that I can find. show int on a switch gives you a status Encapsulation ARPA, loopback not set Keepalive set (10 sec) Auto-duplex, Auto-speed even on a router with a port that do duplex changes ( 3640 NM-4E )there is no status. I don't have access to a router with a port that permits speed and duplex changes.so I can't compare. > > > Thanks Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=57445&t=57431 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: full duplex or half duplex, how can you tell [7:57431]
The Long and Winding Road wrote: > > ""John Tafasi"" wrote in message > news:200211141056.KAA04663@;groupstudy.com... > > Hi, > > > > I have a cisco 2516 router with an ethernet interface. How > can I find out > if > > this inteface is full duplex or half duplex? > > plug it into a full duplex 100 mbs switch port and see if link > occurs? You'd get a link but lots of collisions, eh? The half-duplex side would receive while it was sending, because the full-duplex side would send whenever it wanted. In other words, the 2500 side would report collisions, assuming there was enough simultanesous traffic. I think the best answer is that the 2500 routers pre-date the full-duplex standard. I bet they don't do full-duplex. > > seriously, I believe all routers in the 25xx line are 10/half. > > there is no report on speed and duplex on routers that I can > find. That's annoying. I guess show run would show you a non-default setting, but that's not too helpful. Priscilla > show int > on a switch gives you a status > > Encapsulation ARPA, loopback not set > Keepalive set (10 sec) > Auto-duplex, Auto-speed > > even on a router with a port that do duplex changes ( 3640 > NM-4E )there is > no status. > > I don't have access to a router with a port that permits speed > and duplex > changes.so I can't compare. > > > > > > > > > Thanks > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=57457&t=57431 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: full duplex or half duplex, how can you tell [7:57431]
this is about the comment " You'd get a link but lots of collisions, eh? The half-duplex side would receive while it was sending, because the full-duplex side would send whenever it wanted. In other words, the 2500 side would report collisions, assuming there was enough simultanesous traffic." I hooked up a 2501 eth0 to a 3548 set to full duplex and speed 100. Interestingly the link light on the router lights up but no the switch. The switch sees the total link down and would not even bother sending. I plugged it into an auto-neg port and it obviously worked. Here is the output from switch. Cisco3500-3#sh int fa0/17 FastEthernet0/17 is down, line protocol is down Hardware is Fast Ethernet, address is 0002.fd45.4b91 (bia 0002.fd45.4b91) MTU 1500 bytes, BW 0 Kbit, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive not set Full-duplex, 100Mb/s, 100BaseTX/FX ARP type: ARPA, ARP Timeout 04:00:00 Last input never, output never, output hang never Last clearing of "show interface" counters 1y40w Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 0 multicast 0 input packets with dribble condition detected 0 packets output, 0 bytes, 0 underruns 0 output errors, 0 collisions, 2 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out Cisco3500-3# ""Priscilla Oppenheimer"" wrote in message news:200211141830.SAA03800@;groupstudy.com... > The Long and Winding Road wrote: > > > > ""John Tafasi"" wrote in message > > news:200211141056.KAA04663@;groupstudy.com... > > > Hi, > > > > > > I have a cisco 2516 router with an ethernet interface. How > > can I find out > > if > > > this inteface is full duplex or half duplex? > > > > plug it into a full duplex 100 mbs switch port and see if link > > occurs? > > You'd get a link but lots of collisions, eh? The half-duplex side would > receive while it was sending, because the full-duplex side would send > whenever it wanted. In other words, the 2500 side would report collisions, > assuming there was enough simultanesous traffic. > > I think the best answer is that the 2500 routers pre-date the full-duplex > standard. I bet they don't do full-duplex. > > > > > seriously, I believe all routers in the 25xx line are 10/half. > > > > there is no report on speed and duplex on routers that I can > > find. > > That's annoying. I guess show run would show you a non-default setting, but > that's not too helpful. > > Priscilla > > > show int > > on a switch gives you a status > > > > Encapsulation ARPA, loopback not set > > Keepalive set (10 sec) > > Auto-duplex, Auto-speed > > > > even on a router with a port that do duplex changes ( 3640 > > NM-4E )there is > > no status. > > > > I don't have access to a router with a port that permits speed > > and duplex > > changes.so I can't compare. > > > > > > > > > > > > > > > Thanks Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=57466&t=57431 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: full duplex or half duplex, how can you tell [7:57431]
sam, I think the 2500 series uses the AUI port for Ethernet, so I think this is why the hardware doesn't support 100/full. I guess they had to make sacrifices for flexibility that, in hindsight, probably weren't necessary. GM -Original Message- From: sam sneed [mailto:vristevski@;hotmail.com] Sent: Thursday, November 14, 2002 3:21 PM To: [EMAIL PROTECTED] Subject: Re: full duplex or half duplex, how can you tell [7:57431] this is about the comment " You'd get a link but lots of collisions, eh? The half-duplex side would receive while it was sending, because the full-duplex side would send whenever it wanted. In other words, the 2500 side would report collisions, assuming there was enough simultanesous traffic." I hooked up a 2501 eth0 to a 3548 set to full duplex and speed 100. Interestingly the link light on the router lights up but no the switch. The switch sees the total link down and would not even bother sending. I plugged it into an auto-neg port and it obviously worked. Here is the output from switch. Cisco3500-3#sh int fa0/17 FastEthernet0/17 is down, line protocol is down Hardware is Fast Ethernet, address is 0002.fd45.4b91 (bia 0002.fd45.4b91) MTU 1500 bytes, BW 0 Kbit, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive not set Full-duplex, 100Mb/s, 100BaseTX/FX ARP type: ARPA, ARP Timeout 04:00:00 Last input never, output never, output hang never Last clearing of "show interface" counters 1y40w Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 0 multicast 0 input packets with dribble condition detected 0 packets output, 0 bytes, 0 underruns 0 output errors, 0 collisions, 2 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out Cisco3500-3# ""Priscilla Oppenheimer"" wrote in message news:200211141830.SAA03800@;groupstudy.com... > The Long and Winding Road wrote: > > > > ""John Tafasi"" wrote in message > > news:200211141056.KAA04663@;groupstudy.com... > > > Hi, > > > > > > I have a cisco 2516 router with an ethernet interface. How > > can I find out > > if > > > this inteface is full duplex or half duplex? > > > > plug it into a full duplex 100 mbs switch port and see if link > > occurs? > > You'd get a link but lots of collisions, eh? The half-duplex side would > receive while it was sending, because the full-duplex side would send > whenever it wanted. In other words, the 2500 side would report collisions, > assuming there was enough simultanesous traffic. > > I think the best answer is that the 2500 routers pre-date the full-duplex > standard. I bet they don't do full-duplex. > > > > > seriously, I believe all routers in the 25xx line are 10/half. > > > > there is no report on speed and duplex on routers that I can > > find. > > That's annoying. I guess show run would show you a non-default setting, but > that's not too helpful. > > Priscilla > > > show int > > on a switch gives you a status > > > > Encapsulation ARPA, loopback not set > > Keepalive set (10 sec) > > Auto-duplex, Auto-speed > > > > even on a router with a port that do duplex changes ( 3640 > > NM-4E )there is > > no status. > > > > I don't have access to a router with a port that permits speed > > and duplex > > changes.so I can't compare. > > > > > > > > > > > > > > > Thanks Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=57469&t=57431 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: full duplex or half duplex, how can you tell [7:57431]
The Long and Winding Road wrote: > > ""John Tafasi"" wrote in message > news:200211141056.KAA04663@;groupstudy.com... > > Hi, > > > > I have a cisco 2516 router with an ethernet interface. How > can I find out > if > > this inteface is full duplex or half duplex? > > plug it into a full duplex 100 mbs switch port and see if link > occurs? > > seriously, I believe all routers in the 25xx line are 10/half. > > there is no report on speed and duplex on routers that I can > find. show int > on a switch gives you a status > > Encapsulation ARPA, loopback not set > Keepalive set (10 sec) > Auto-duplex, Auto-speed > > even on a router with a port that do duplex changes ( 3640 > NM-4E )there is > no status. > Interesting - I'd never twigged to this. A FastEthernet port certainly gives this information Full-duplex, 100Mb/s, 100BaseTX/FX but an ethernet port on the same router (a 3600) doesn't show it. I'd guess that the code for 'show ethernet' on the routers that do support full-duplex comes straight from the routers that don't support it ;-) > I don't have access to a router with a port that permits speed > and duplex > changes.so I can't compare. > > > > > > > > > Thanks > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=57471&t=57431 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: full duplex or half duplex, how can you tell [7:57431]
sam sneed wrote: > > this is about the comment > > " You'd get a link but lots of collisions, eh? The half-duplex > side would > receive while it was sending, because the full-duplex side > would send > whenever it wanted. In other words, the 2500 side would report > collisions, > assuming there was enough simultanesous traffic." > > I hooked up a 2501 eth0 to a 3548 set to full duplex and speed > 100. > Interestingly the link light on the router lights up but no the > switch. That's probably because of the speed mismatch not the duplex mismatch? In some cases you can get a link light and think everything is fine, when actually there are problems due to a duplex mismtach. I don't have the equipment to show you an example, but I know I've seen it. Needless to say, it makes troubleshooting difficult. Priscilla > The > switch sees the total link down and would not even bother > sending. I plugged > it into an auto-neg port and it obviously worked. Here is the > output from > switch. > > Cisco3500-3#sh int fa0/17 > FastEthernet0/17 is down, line protocol is down > Hardware is Fast Ethernet, address is 0002.fd45.4b91 (bia > 0002.fd45.4b91) > MTU 1500 bytes, BW 0 Kbit, DLY 100 usec, > reliability 255/255, txload 1/255, rxload 1/255 > Encapsulation ARPA, loopback not set > Keepalive not set > Full-duplex, 100Mb/s, 100BaseTX/FX > ARP type: ARPA, ARP Timeout 04:00:00 > Last input never, output never, output hang never > Last clearing of "show interface" counters 1y40w > Queueing strategy: fifo > Output queue 0/40, 0 drops; input queue 0/75, 0 drops > 5 minute input rate 0 bits/sec, 0 packets/sec > 5 minute output rate 0 bits/sec, 0 packets/sec > 0 packets input, 0 bytes > Received 0 broadcasts, 0 runts, 0 giants, 0 throttles > 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored > 0 watchdog, 0 multicast > 0 input packets with dribble condition detected > 0 packets output, 0 bytes, 0 underruns > 0 output errors, 0 collisions, 2 interface resets > 0 babbles, 0 late collision, 0 deferred > 0 lost carrier, 0 no carrier > 0 output buffer failures, 0 output buffers swapped out > Cisco3500-3# > > > > > > ""Priscilla Oppenheimer"" wrote in > message > news:200211141830.SAA03800@;groupstudy.com... > > The Long and Winding Road wrote: > > > > > > ""John Tafasi"" wrote in message > > > news:200211141056.KAA04663@;groupstudy.com... > > > > Hi, > > > > > > > > I have a cisco 2516 router with an ethernet interface. How > > > can I find out > > > if > > > > this inteface is full duplex or half duplex? > > > > > > plug it into a full duplex 100 mbs switch port and see if > link > > > occurs? > > > > You'd get a link but lots of collisions, eh? The half-duplex > side would > > receive while it was sending, because the full-duplex side > would send > > whenever it wanted. In other words, the 2500 side would > report collisions, > > assuming there was enough simultanesous traffic. > > > > I think the best answer is that the 2500 routers pre-date the > full-duplex > > standard. I bet they don't do full-duplex. > > > > > > > > seriously, I believe all routers in the 25xx line are > 10/half. > > > > > > there is no report on speed and duplex on routers that I can > > > find. > > > > That's annoying. I guess show run would show you a > non-default setting, > but > > that's not too helpful. > > > > Priscilla > > > > > show int > > > on a switch gives you a status > > > > > > Encapsulation ARPA, loopback not set > > > Keepalive set (10 sec) > > > Auto-duplex, Auto-speed > > > > > > even on a router with a port that do duplex changes ( 3640 > > > NM-4E )there is > > > no status. > > > > > > I don't have access to a router with a port that permits > speed > > > and duplex > > > changes.so I can't compare. > > > > > > > > > > > > > > > > > > > > > Thanks > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=57472&t=57431 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: full duplex or half duplex, how can you tell [7:57431]
That was correct. I changed the speed to 10 full duplex and got the link a both sides. I just thought it was odd that one side(router) had the link light on but the switch didn't. Cisco3500-3#sh int fa0/17 FastEthernet0/17 is up, line protocol is up Hardware is Fast Ethernet, address is 0002.fd45.4b91 (bia 0002.fd45.4b91) MTU 1500 bytes, BW 1 Kbit, DLY 1000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive not set Full-duplex, 10Mb/s, 100BaseTX/FX ""Priscilla Oppenheimer"" wrote in message news:200211142203.WAA18335@;groupstudy.com... > sam sneed wrote: > > > > this is about the comment > > > > " You'd get a link but lots of collisions, eh? The half-duplex > > side would > > receive while it was sending, because the full-duplex side > > would send > > whenever it wanted. In other words, the 2500 side would report > > collisions, > > assuming there was enough simultanesous traffic." > > > > I hooked up a 2501 eth0 to a 3548 set to full duplex and speed > > 100. > > Interestingly the link light on the router lights up but no the > > switch. > > That's probably because of the speed mismatch not the duplex mismatch? > > In some cases you can get a link light and think everything is fine, when > actually there are problems due to a duplex mismtach. > > I don't have the equipment to show you an example, but I know I've seen it. > Needless to say, it makes troubleshooting difficult. > > Priscilla > > > The > > switch sees the total link down and would not even bother > > sending. I plugged > > it into an auto-neg port and it obviously worked. Here is the > > output from > > switch. > > > > Cisco3500-3#sh int fa0/17 > > FastEthernet0/17 is down, line protocol is down > > Hardware is Fast Ethernet, address is 0002.fd45.4b91 (bia > > 0002.fd45.4b91) > > MTU 1500 bytes, BW 0 Kbit, DLY 100 usec, > > reliability 255/255, txload 1/255, rxload 1/255 > > Encapsulation ARPA, loopback not set > > Keepalive not set > > Full-duplex, 100Mb/s, 100BaseTX/FX > > ARP type: ARPA, ARP Timeout 04:00:00 > > Last input never, output never, output hang never > > Last clearing of "show interface" counters 1y40w > > Queueing strategy: fifo > > Output queue 0/40, 0 drops; input queue 0/75, 0 drops > > 5 minute input rate 0 bits/sec, 0 packets/sec > > 5 minute output rate 0 bits/sec, 0 packets/sec > > 0 packets input, 0 bytes > > Received 0 broadcasts, 0 runts, 0 giants, 0 throttles > > 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored > > 0 watchdog, 0 multicast > > 0 input packets with dribble condition detected > > 0 packets output, 0 bytes, 0 underruns > > 0 output errors, 0 collisions, 2 interface resets > > 0 babbles, 0 late collision, 0 deferred > > 0 lost carrier, 0 no carrier > > 0 output buffer failures, 0 output buffers swapped out > > Cisco3500-3# > > > > > > > > > > > > ""Priscilla Oppenheimer"" wrote in > > message > > news:200211141830.SAA03800@;groupstudy.com... > > > The Long and Winding Road wrote: > > > > > > > > ""John Tafasi"" wrote in message > > > > news:200211141056.KAA04663@;groupstudy.com... > > > > > Hi, > > > > > > > > > > I have a cisco 2516 router with an ethernet interface. How > > > > can I find out > > > > if > > > > > this inteface is full duplex or half duplex? > > > > > > > > plug it into a full duplex 100 mbs switch port and see if > > link > > > > occurs? > > > > > > You'd get a link but lots of collisions, eh? The half-duplex > > side would > > > receive while it was sending, because the full-duplex side > > would send > > > whenever it wanted. In other words, the 2500 side would > > report collisions, > > > assuming there was enough simultanesous traffic. > > > > > > I think the best answer is that the 2500 routers pre-date the > > full-duplex > > > standard. I bet they don't do full-duplex. > > > > > > > > > > > seriously, I believe all routers in the 25xx line are > > 10/half. > > > > > > > > there is no report on speed and duplex on routers that I can > > > > find. > > > > > > That's annoying. I guess show run would show you a > > non-default setting, > > but > > > that's not too helpful. > > > > > > Priscilla > > > > > > > show int > > > > on a switch gives you a status > > > > > > > > Encapsulation ARPA, loopback not set > > > > Keepalive set (10 sec) > > > > Auto-duplex, Auto-speed > > > > > > > > even on a router with a port that do duplex changes ( 3640 > > > > NM-4E )there is > > > > no status. > > > > > > > > I don't have access to a router with a port that permits > > speed > > > > and duplex > > > > changes.so I can't compare. > > > > > > > > > > > > > > > > > > > > > > > > > > > Thanks Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=57474&t=57431 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nond
Re: full duplex or half duplex, how can you tell [7:57431]
Heck when the 2500 was first introduced I don't know if 100M was even available and even if it was the CPU couldn't handle it. The 2514 could not drive it's 2 ethernets! Dave "Mossburg, Geoff (MAN-Corporate)" wrote: > > sam, > I think the 2500 series uses the AUI port for Ethernet, so I think > this is why the hardware doesn't support 100/full. I guess they had to make > sacrifices for flexibility that, in hindsight, probably weren't necessary. > GM > > -Original Message- > From: sam sneed [mailto:vristevski@;hotmail.com] > Sent: Thursday, November 14, 2002 3:21 PM > To: [EMAIL PROTECTED] > Subject: Re: full duplex or half duplex, how can you tell [7:57431] > > this is about the comment > > " You'd get a link but lots of collisions, eh? The half-duplex side would > receive while it was sending, because the full-duplex side would send > whenever it wanted. In other words, the 2500 side would report collisions, > assuming there was enough simultanesous traffic." > > I hooked up a 2501 eth0 to a 3548 set to full duplex and speed 100. > Interestingly the link light on the router lights up but no the switch. The > switch sees the total link down and would not even bother sending. I plugged > it into an auto-neg port and it obviously worked. Here is the output from > switch. > > Cisco3500-3#sh int fa0/17 > FastEthernet0/17 is down, line protocol is down > Hardware is Fast Ethernet, address is 0002.fd45.4b91 (bia 0002.fd45.4b91) > MTU 1500 bytes, BW 0 Kbit, DLY 100 usec, > reliability 255/255, txload 1/255, rxload 1/255 > Encapsulation ARPA, loopback not set > Keepalive not set > Full-duplex, 100Mb/s, 100BaseTX/FX > ARP type: ARPA, ARP Timeout 04:00:00 > Last input never, output never, output hang never > Last clearing of "show interface" counters 1y40w > Queueing strategy: fifo > Output queue 0/40, 0 drops; input queue 0/75, 0 drops > 5 minute input rate 0 bits/sec, 0 packets/sec > 5 minute output rate 0 bits/sec, 0 packets/sec > 0 packets input, 0 bytes > Received 0 broadcasts, 0 runts, 0 giants, 0 throttles > 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored > 0 watchdog, 0 multicast > 0 input packets with dribble condition detected > 0 packets output, 0 bytes, 0 underruns > 0 output errors, 0 collisions, 2 interface resets > 0 babbles, 0 late collision, 0 deferred > 0 lost carrier, 0 no carrier > 0 output buffer failures, 0 output buffers swapped out > Cisco3500-3# > > ""Priscilla Oppenheimer"" wrote in message > news:200211141830.SAA03800@;groupstudy.com... > > The Long and Winding Road wrote: > > > > > > ""John Tafasi"" wrote in message > > > news:200211141056.KAA04663@;groupstudy.com... > > > > Hi, > > > > > > > > I have a cisco 2516 router with an ethernet interface. How > > > can I find out > > > if > > > > this inteface is full duplex or half duplex? > > > > > > plug it into a full duplex 100 mbs switch port and see if link > > > occurs? > > > > You'd get a link but lots of collisions, eh? The half-duplex side would > > receive while it was sending, because the full-duplex side would send > > whenever it wanted. In other words, the 2500 side would report collisions, > > assuming there was enough simultanesous traffic. > > > > I think the best answer is that the 2500 routers pre-date the full-duplex > > standard. I bet they don't do full-duplex. > > > > > > > > seriously, I believe all routers in the 25xx line are 10/half. > > > > > > there is no report on speed and duplex on routers that I can > > > find. > > > > That's annoying. I guess show run would show you a non-default setting, > but > > that's not too helpful. > > > > Priscilla > > > > > show int > > > on a switch gives you a status > > > > > > Encapsulation ARPA, loopback not set > > > Keepalive set (10 sec) > > > Auto-duplex, Auto-speed > > > > > > even on a router with a port that do duplex changes ( 3640 > > > NM-4E )there is > > > no status. > > > > > > I don't have access to a router with a port that permits speed > > > and duplex > > > changes.so I can't compare. > > > > > > > > > > > > > > > > > > > > > Thanks -- David Madland CCIE# 2016 Sr. Network Engineer Qwest Communications 612-664-3367 "You don't make the poor richer by making the rich poorer." --Winston Churchill Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=57475&t=57431 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: full duplex or half duplex, how can you tell [7:57431]
Wow! Two ethernets! Bonus! I once worked on a 2501 and I only had one ethernet...AND it was AUI! --Mark Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=57519&t=57431 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: full duplex or half duplex, how can you tell [7:57431]
Priscilla Oppenheimer wrote: > > sam sneed wrote: > > > > this is about the comment > > > > " You'd get a link but lots of collisions, eh? The half-duplex > > side would > > receive while it was sending, because the full-duplex side > > would send > > whenever it wanted. In other words, the 2500 side would report > > collisions, > > assuming there was enough simultanesous traffic." > > > > I hooked up a 2501 eth0 to a 3548 set to full duplex and speed > > 100. > > Interestingly the link light on the router lights up but no the > > switch. > > That's probably because of the speed mismatch not the duplex mismatch? > > In some cases you can get a link light and think everything is fine, when > actually there are problems due to a duplex mismtach. > Only a speed issue, not a duplex issue. When the 10/100 side is hard set to 100Mb so that it doesn't negotiate nor autosense, and the other side is a legacy 10Mb/half interface, then the 10Mb side will get a false link indication. The 100Mb fast link pulses produce enough energy in the band where the 10Mb interface is looking for them, to fool it. The 100Mb side will correctly show no link. The tip off is that the 10Mb side sees zero valid input frames in its counters. The 100Mb transmitter appears to be forever streaming. - Marty Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=57672&t=57431 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]