RE: why can ping but traceroute stop half way
Hope i can answer your questions. Some of the routers disable ICMP response. Thus, they will not reply you but able to route packet through and the host you ping to will reply your ICMP packets. Rgds, Sam > -Original Message- > From: Sim, CT (Chee Tong) [SMTP:[EMAIL PROTECTED]] > Sent: Monday, December 04, 2000 5:05 PM > To: [EMAIL PROTECTED] > Subject: why can ping but traceroute stop half way > > Hi..Dear all, > > i wonder why I can ping to a site but when I do a traceroute stop half > way.. > I thought traceroute are based on ICMP as well?? See below > > > sin-uunet>ping 210.24.136.242 > Type escape sequence to abort. > Sending 5, 100-byte ICMP Echos to 210.24.136.242, timeout is 2 seconds: > ! > Success rate is 100 percent (5/5), round-trip min/avg/max = 32/96/156 ms > sin-uunet>traceroute 210.24.136.242 > > Type escape sequence to abort. > Tracing the route to 210.24.136.242 > > 1 Loopback0.GW2.SIN1.Alter.Net (210.80.0.25) 12 msec 12 msec 12 msec > 2 322.ATM5-0-0.XR2.SIN1.Alter.Net (210.80.3.65) 8 msec 12 msec 8 msec > 3 412.ATM8-0-0.GW1.SIN1.Alter.Net (210.80.3.62) 12 msec 12 msec 8 msec > 4 202.95.96.30 20 msec 16 msec 16 msec > 5 scipk017.pacific.net.sg (203.120.90.17) 12 msec 16 msec 16 msec > 6 202.42.42.234 20 msec 92 msec 36 msec > 7 * * * > 8 * * * > 9 * * * > > == > De informatie opgenomen in dit bericht kan vertrouwelijk zijn en > is uitsluitend bestemd voor de geadresseerde. Indien u dit bericht > onterecht ontvangt wordt u verzocht de inhoud niet te gebruiken en > de afzender direct te informeren door het bericht te retourneren. > == > The information contained in this message may be confidential > and is intended to be exclusively for the addressee. Should you > receive this message unintentionally, please do not use the contents > herein and notify the sender immediately by return e-mail. > > > == > > _ > FAQ, list archives, and subscription info: > http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: why can ping but traceroute stop half way
Weird. Within UUNET network from AU: Tracing route to 210.24.136.242 over a maximum of 30 hops 1 110 ms 110 ms 110 ms tnt7.syd2.da.uu.net [63.12.31.206] 2 101 ms 100 ms 110 ms 63.12.150.1 3 100 ms 111 ms 100 ms 351.ATM3-0-0.XR1.SYD2.Alter.Net [210.80.3.225] 4 100 ms 120 ms 121 ms ATM5-0-0.TR1.SYD2.Alter.Net [210.80.48.133] 5 581 ms 600 ms 591 ms 296.ATM9-0-0.TR1.SIN1.Alter.Net [210.80.48.173] 6 580 ms 591 ms 591 ms POS1-0-0.XR1.SIN1.Alter.Net [210.80.48.50] 7 641 ms 611 ms 591 ms 311.ATM5-0-0.GW1.SIN1.Alter.Net [210.80.3.42] 8 591 ms 581 ms 591 ms 202.95.96.30 9 580 ms 591 ms 591 ms scipk017.pacific.net.sg [203.120.90.17] 10 1522 ms 821 ms 872 ms 202.42.42.234 11 791 ms 921 ms 831 ms 210.24.136.242 Tracing from GW2.SIN1(where you're connected)...from SG GW2.SIN1#tr 210.24.136.242 Type escape sequence to abort. Tracing the route to 210.24.136.242 1 422.ATM8-0-0.XR1.SIN1.Alter.Net (210.80.3.45) 0 msec 2 412.ATM8-0-0.GW1.SIN1.Alter.Net (210.80.3.62) 4 msec 3 202.95.96.30 188 msec 368 msec 484 msec 4 scipk017.pacific.net.sg (203.120.90.17) [AS 4628] 176 msec 116 msec 136 msec 5 202.42.42.234 [AS 4628] 204 msec 116 msec 120 msec 6 * * * Would anyone like to explain why (still in uunet network) this happens? Without doing much research(cuz im at home)... Thanks, Brandon -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of SAM Meng Wai Sent: Monday, December 04, 2000 2:11 AM To: 'Sim, CT (Chee Tong)'; [EMAIL PROTECTED] Subject: RE: why can ping but traceroute stop half way Hope i can answer your questions. Some of the routers disable ICMP response. Thus, they will not reply you but able to route packet through and the host you ping to will reply your ICMP packets. Rgds, Sam > -Original Message- > From: Sim, CT (Chee Tong) [SMTP:[EMAIL PROTECTED]] > Sent: Monday, December 04, 2000 5:05 PM > To: [EMAIL PROTECTED] > Subject: why can ping but traceroute stop half way > > Hi..Dear all, > > i wonder why I can ping to a site but when I do a traceroute stop half > way.. > I thought traceroute are based on ICMP as well?? See below > > > sin-uunet>ping 210.24.136.242 > Type escape sequence to abort. > Sending 5, 100-byte ICMP Echos to 210.24.136.242, timeout is 2 seconds: > ! > Success rate is 100 percent (5/5), round-trip min/avg/max = 32/96/156 ms > sin-uunet>traceroute 210.24.136.242 > > Type escape sequence to abort. > Tracing the route to 210.24.136.242 > > 1 Loopback0.GW2.SIN1.Alter.Net (210.80.0.25) 12 msec 12 msec 12 msec > 2 322.ATM5-0-0.XR2.SIN1.Alter.Net (210.80.3.65) 8 msec 12 msec 8 msec > 3 412.ATM8-0-0.GW1.SIN1.Alter.Net (210.80.3.62) 12 msec 12 msec 8 msec > 4 202.95.96.30 20 msec 16 msec 16 msec > 5 scipk017.pacific.net.sg (203.120.90.17) 12 msec 16 msec 16 msec > 6 202.42.42.234 20 msec 92 msec 36 msec > 7 * * * > 8 * * * > 9 * * * > > == > De informatie opgenomen in dit bericht kan vertrouwelijk zijn en > is uitsluitend bestemd voor de geadresseerde. Indien u dit bericht > onterecht ontvangt wordt u verzocht de inhoud niet te gebruiken en > de afzender direct te informeren door het bericht te retourneren. > == > The information contained in this message may be confidential > and is intended to be exclusively for the addressee. Should you > receive this message unintentionally, please do not use the contents > herein and notify the sender immediately by return e-mail. > > > == > > _ > FAQ, list archives, and subscription info: > http://www.groupstudy.com/list/cisco.html > Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: why can ping but traceroute stop half way
I believe, but am willing to be shot down in flames if I'm wrong that Traceroute uses different port numbers to ICMP. I've allowed ICMP through firewalls before, then tried to traceroute and the trace has been dropped. The destination port being dropped was logged as something like 34543 and incremented by one for each hop (thats not the exact number but it's in that order-5 figures). If you try an extended trace the default port number (last requirement) is around that mark too. I know how a ping works (increasing TTL for each hop, but on a fixed port) but not sure at all of trace route. Is there any way to fix the traceroute port, or am I barking up the wrong tree? Been wondering about this for a while. Anybody care to put me out of my misery. (Or do I take another side track and find out myself) Cheers, Gaz ""Brandon Peyton"" <[EMAIL PROTECTED]> wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > Weird. > > Within UUNET network from AU: > > Tracing route to 210.24.136.242 over a maximum of 30 hops > > 1 110 ms 110 ms 110 ms tnt7.syd2.da.uu.net [63.12.31.206] > 2 101 ms 100 ms 110 ms 63.12.150.1 > 3 100 ms 111 ms 100 ms 351.ATM3-0-0.XR1.SYD2.Alter.Net > [210.80.3.225] > 4 100 ms 120 ms 121 ms ATM5-0-0.TR1.SYD2.Alter.Net [210.80.48.133] > 5 581 ms 600 ms 591 ms 296.ATM9-0-0.TR1.SIN1.Alter.Net > [210.80.48.173] > > 6 580 ms 591 ms 591 ms POS1-0-0.XR1.SIN1.Alter.Net [210.80.48.50] > 7 641 ms 611 ms 591 ms 311.ATM5-0-0.GW1.SIN1.Alter.Net > [210.80.3.42] > 8 591 ms 581 ms 591 ms 202.95.96.30 > 9 580 ms 591 ms 591 ms scipk017.pacific.net.sg [203.120.90.17] > 10 1522 ms 821 ms 872 ms 202.42.42.234 > 11 791 ms 921 ms 831 ms 210.24.136.242 > > > Tracing from GW2.SIN1(where you're connected)...from SG > > GW2.SIN1#tr 210.24.136.242 > > Type escape sequence to abort. > Tracing the route to 210.24.136.242 > > 1 422.ATM8-0-0.XR1.SIN1.Alter.Net (210.80.3.45) 0 msec > 2 412.ATM8-0-0.GW1.SIN1.Alter.Net (210.80.3.62) 4 msec > 3 202.95.96.30 188 msec 368 msec 484 msec > 4 scipk017.pacific.net.sg (203.120.90.17) [AS 4628] 176 msec 116 msec 136 > msec > 5 202.42.42.234 [AS 4628] 204 msec 116 msec 120 msec > 6 * * * > > Would anyone like to explain why (still in uunet network) this happens? > Without doing much research(cuz im at home)... > > Thanks, > Brandon > > > > -Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of > SAM Meng Wai > Sent: Monday, December 04, 2000 2:11 AM > To: 'Sim, CT (Chee Tong)'; [EMAIL PROTECTED] > Subject: RE: why can ping but traceroute stop half way > > > Hope i can answer your questions. Some of the routers disable ICMP > response. Thus, they will not reply you but able to route packet through > and the host you ping to will reply your ICMP packets. > > Rgds, > Sam > > > > -Original Message- > > From: Sim, CT (Chee Tong) [SMTP:[EMAIL PROTECTED]] > > Sent: Monday, December 04, 2000 5:05 PM > > To: [EMAIL PROTECTED] > > Subject: why can ping but traceroute stop half way > > > > Hi..Dear all, > > > > i wonder why I can ping to a site but when I do a traceroute stop half > > way.. > > I thought traceroute are based on ICMP as well?? See below > > > > > > sin-uunet>ping 210.24.136.242 > > Type escape sequence to abort. > > Sending 5, 100-byte ICMP Echos to 210.24.136.242, timeout is 2 seconds: > > ! > > Success rate is 100 percent (5/5), round-trip min/avg/max = 32/96/156 ms > > sin-uunet>traceroute 210.24.136.242 > > > > Type escape sequence to abort. > > Tracing the route to 210.24.136.242 > > > > 1 Loopback0.GW2.SIN1.Alter.Net (210.80.0.25) 12 msec 12 msec 12 msec > > 2 322.ATM5-0-0.XR2.SIN1.Alter.Net (210.80.3.65) 8 msec 12 msec 8 msec > > 3 412.ATM8-0-0.GW1.SIN1.Alter.Net (210.80.3.62) 12 msec 12 msec 8 msec > > 4 202.95.96.30 20 msec 16 msec 16 msec > > 5 scipk017.pacific.net.sg (203.120.90.17) 12 msec 16 msec 16 msec > > 6 202.42.42.234 20 msec 92 msec 36 msec > > 7 * * * > > 8 * * * > > 9 * * * > > > > == > > De informatie opgenomen in dit bericht kan vertrouwelijk zijn en > > is uitsluitend bestemd voor de geadresseerde. Indien u dit bericht > > onterecht ontvangt wordt u verzocht de inhoud niet te gebruiken en > > de afzender direct te informeren door het bericht te retourneren. > > ===
RE: why can ping but traceroute stop half way
Most versions of traceroute (including Cisco's I believe) use UDP echo packets rather than ICMP echo. There may be a router or a firewall that is blocking the UDP echoes while allowing the ICMP echoes through. Microsoft's tracert command in Windows 95/98 uses ICMP. You might want to try the same test from a Windows PC and see what you get. Rick -Original Message- From: Sim, CT (Chee Tong) [mailto:[EMAIL PROTECTED]] Sent: Monday, December 04, 2000 4:05 AM To: [EMAIL PROTECTED] Subject: why can ping but traceroute stop half way Hi..Dear all, i wonder why I can ping to a site but when I do a traceroute stop half way.. I thought traceroute are based on ICMP as well?? See below sin-uunet>ping 210.24.136.242 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 210.24.136.242, timeout is 2 seconds: ! Success rate is 100 percent (5/5), round-trip min/avg/max = 32/96/156 ms sin-uunet>traceroute 210.24.136.242 Type escape sequence to abort. Tracing the route to 210.24.136.242 1 Loopback0.GW2.SIN1.Alter.Net (210.80.0.25) 12 msec 12 msec 12 msec 2 322.ATM5-0-0.XR2.SIN1.Alter.Net (210.80.3.65) 8 msec 12 msec 8 msec 3 412.ATM8-0-0.GW1.SIN1.Alter.Net (210.80.3.62) 12 msec 12 msec 8 msec 4 202.95.96.30 20 msec 16 msec 16 msec 5 scipk017.pacific.net.sg (203.120.90.17) 12 msec 16 msec 16 msec 6 202.42.42.234 20 msec 92 msec 36 msec 7 * * * 8 * * * 9 * * * == De informatie opgenomen in dit bericht kan vertrouwelijk zijn en is uitsluitend bestemd voor de geadresseerde. Indien u dit bericht onterecht ontvangt wordt u verzocht de inhoud niet te gebruiken en de afzender direct te informeren door het bericht te retourneren. == The information contained in this message may be confidential and is intended to be exclusively for the addressee. Should you receive this message unintentionally, please do not use the contents herein and notify the sender immediately by return e-mail. == _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED] _ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: why can ping but traceroute stop half way
For traceroute, Cisco and most Unix platforms use an outgoing frame that goes to a large UDP port number, starting with 33434. This allows the frame to get past routers and to the end station, which should send a Destination Unreachable, Port Unreachable. Newer vendor implementations (like Microsoft) use ICMP Echo (ping) for the outgoing frame. The routers in the path return Destination Unreachable, TTL Exceeded. The end node sends Destination Unreachable, Port Unreachable for Cisco, et. al. For Microsoft the end node should just send a normal Ping response. So writing access lists, and getting through access lists, can get a bit complicated. Priscilla At 06:33 PM 12/4/00, Gareth Hinton wrote: >I believe, but am willing to be shot down in flames if I'm wrong that >Traceroute uses different port numbers to ICMP. I've allowed ICMP through >firewalls before, then tried to traceroute and the trace has been dropped. >The destination port being dropped was logged as something like 34543 and >incremented by one for each hop (thats not the exact number but it's in that >order-5 figures). >If you try an extended trace the default port number (last requirement) is >around that mark too. > >I know how a ping works (increasing TTL for each hop, but on a fixed port) >but not sure at all of trace route. Is there any way to fix the traceroute >port, or am I barking up the wrong tree? > >Been wondering about this for a while. Anybody care to put me out of my >misery. (Or do I take another side track and find out myself) > >Cheers, > >Gaz > >""Brandon Peyton"" <[EMAIL PROTECTED]> wrote in message >[EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > Weird. > > > > Within UUNET network from AU: > > > > Tracing route to 210.24.136.242 over a maximum of 30 hops > > > > 1 110 ms 110 ms 110 ms tnt7.syd2.da.uu.net [63.12.31.206] > > 2 101 ms 100 ms 110 ms 63.12.150.1 > > 3 100 ms 111 ms 100 ms 351.ATM3-0-0.XR1.SYD2.Alter.Net > > [210.80.3.225] > > 4 100 ms 120 ms 121 ms ATM5-0-0.TR1.SYD2.Alter.Net >[210.80.48.133] > > 5 581 ms 600 ms 591 ms 296.ATM9-0-0.TR1.SIN1.Alter.Net > > [210.80.48.173] > > > > 6 580 ms 591 ms 591 ms POS1-0-0.XR1.SIN1.Alter.Net [210.80.48.50] > > 7 641 ms 611 ms 591 ms 311.ATM5-0-0.GW1.SIN1.Alter.Net > > [210.80.3.42] > > 8 591 ms 581 ms 591 ms 202.95.96.30 > > 9 580 ms 591 ms 591 ms scipk017.pacific.net.sg [203.120.90.17] > > 10 1522 ms 821 ms 872 ms 202.42.42.234 > > 11 791 ms 921 ms 831 ms 210.24.136.242 > > > > > > Tracing from GW2.SIN1(where you're connected)...from SG > > > > GW2.SIN1#tr 210.24.136.242 > > > > Type escape sequence to abort. > > Tracing the route to 210.24.136.242 > > > > 1 422.ATM8-0-0.XR1.SIN1.Alter.Net (210.80.3.45) 0 msec > > 2 412.ATM8-0-0.GW1.SIN1.Alter.Net (210.80.3.62) 4 msec > > 3 202.95.96.30 188 msec 368 msec 484 msec > > 4 scipk017.pacific.net.sg (203.120.90.17) [AS 4628] 176 msec 116 msec >136 > > msec > > 5 202.42.42.234 [AS 4628] 204 msec 116 msec 120 msec > > 6 * * * > > > > Would anyone like to explain why (still in uunet network) this happens? > > Without doing much research(cuz im at home)... > > > > Thanks, > > Brandon > > > > > > > > -Original Message- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of > > SAM Meng Wai > > Sent: Monday, December 04, 2000 2:11 AM > > To: 'Sim, CT (Chee Tong)'; [EMAIL PROTECTED] > > Subject: RE: why can ping but traceroute stop half way > > > > > > Hope i can answer your questions. Some of the routers disable ICMP > > response. Thus, they will not reply you but able to route packet through > > and the host you ping to will reply your ICMP packets. > > > > Rgds, > > Sam > > > > > > > -Original Message- > > > From: Sim, CT (Chee Tong) [SMTP:[EMAIL PROTECTED]] > > > Sent: Monday, December 04, 2000 5:05 PM > > > To: [EMAIL PROTECTED] > > > Subject: why can ping but traceroute stop half way > > > > > > Hi..Dear all, > > > > > > i wonder why I can ping to a site but when I do a traceroute stop half > > > way.. > > > I thought traceroute are based on ICMP as well?? See below > > > > > > > > > sin-uunet>ping 210.24.136.242 > > > Type escape sequence to abort. > > > Sending 5, 100-byte ICMP Echos to 210.24.136.242, tim
