1. CISCO NETWORKING ACADEMY Chabot College ELEC 99.08 ping & traceroute

2. CISCO NETWORKING ACADEMY ICMP ICMP = Internet Control Message Protocol Layer 3 Part of TCP/IP suite of protocols

3. CISCO NETWORKING ACADEMY ICMP

4. ICMP Echo Request Called “ping” Important network testing tool Tests connectivity at layers 3-1 Most TCP/IP hosts can send pings –PCs –routers All TCP/IP hosts will reply to pings (unless configured to discard them for security reasons.)

5. CISCO NETWORKING ACADEMY DOS Ping Display C:\WINDOWS>ping 172.28.118.1 Pinging 172.28.118.1 with 32 bytes of data: Reply from 172.28.118.1: bytes=32 time=1ms TTL=255 Ping statistics for 172.28.118.1: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 1ms, Maximum = 1ms, Average = 1ms Key results Successful replies

6. CISCO NETWORKING ACADEMY Cisco IOS Ping Display Differs in format from DOS display Contains same information You’ll work with IOS ping in an upcoming lab.

7. CISCO NETWORKING ACADEMY ICMP Echo Request To check the configuration of layer 3-1 on your PC, you can ping a special internal test address - the loopback address. Try it now - –Open a DOS window –>ping 127.0.0.1

8. CISCO NETWORKING ACADEMY ICMP Echo Request To check the configuration of layer 3-1 between your PC and another host, you can ping that host’s address. Try it now - –Open a DOS window –>ping 172.28.118.10

9. CISCO NETWORKING ACADEMY ICMP Echo Request You can also use hostnames in the ping command (if DNS is running, or host tables are enabled). Try it now - –Open a DOS window –>ping academy1

10. CISCO NETWORKING ACADEMY Traceroute Tool used to trace path from source to destination host. TCP/IP not designed for traceroute, so it is sometimes unpredictable.

11. CISCO NETWORKING ACADEMY Traceroute Packets Most traceroute programs, including the Cisco IOS traceroute, send UDP packets (User Datagram Protocol). Micrososft tracert sends ICMP echo request (ping) packets.

12. CISCO NETWORKING ACADEMY Traceroute Command Unix: traceroute Cisco IOS: traceroute (trace) DOS: tracert

13. CISCO NETWORKING ACADEMY Traceroute Operation Transmits packets with small Time-To- Live (TTL) values. –First packets have TTL = 1 –Second have TTL = 2 –Third have TTL = 3 –etc.

14. CISCO NETWORKING ACADEMY Time to Live Field TTL

15. CISCO NETWORKING ACADEMY Traceroute Operation Generates messages from each router used along the path. Every router that handles a packet subtracts one from the packet's TTL. If the TTL reaches zero, the packet has expired and is discarded. At that point, most routers send an ICMP Time Exceeded message back to the sender - traceroute uses this message. A TTL value of one should produce a message from the first router; two from the second; etc.

16. CISCO NETWORKING ACADEMY Traceroute Operation

17. CISCO NETWORKING ACADEMY Traceroute Documentation Cisco has documented the operation and use of traceroute at http://www.cisco.com/warp/public/105/traceroute.shtml http://www.cisco.com/warp/public/105/traceroute.shtml

18. CISCO NETWORKING ACADEMY DOS Traceroute Display C:\WINDOWS>tracert www.husd.k12.ca.us Tracing route to www.husd.k12.ca.us [206.110.193.5] over a maximum of 30 hops: 1 1 ms 1 ms 1 ms 192.168.0.1 2 23 ms 32 ms 32 ms adsl-63-198-176-254.dsl.snfc21.pacbell.net [63.198.176.254] 3 20 ms 19 ms 21 ms core4-g3-0.snfc21.pbi.net [216.102.187.130] 4 20 ms 19 ms 19 ms ded2-fa12-0-0.snfc21.pbi.net [209.232.130.5] 5 25 ms 51 ms 21 ms vip-Alameda-Co.cust-rtr.pacbell.net [216.102.184.2] 6 44 ms 37 ms 43 ms 206.110.252.174 7 47 ms 40 ms 40 ms www.husd.k12.ca.us [206.110.193.5] Trace complete. Round trip time Hop Router

19. CISCO NETWORKING ACADEMY DOS Traceroute Try it now - –Open a DOS window: –>tracert porter –>tracert www.husd.k12.ca.us

20. CISCO NETWORKING ACADEMY Cisco IOS Traceroute Display Differs in format from DOS display Contains same information You’ll work with IOS trace in an upcoming lab.

21. CISCO NETWORKING ACADEMY Cisco IOS Traceroute Try it now - –Start Router e-SIM –Give all your routers a configuration: click SHOW DONE in the row of SET buttons at the bottom, click A, B, C, D, E click HIDE DONE –Login - Password - cisco –Lab_A> trace Lab_E –Lab_A> trace 210.93.105.2 –click SHOW TOPOLOGY and compare to the trace results...