Troubleshooting Network!!!! what it actually meant By? Is it a network who is sick or Is it a network with failure equipment's and finding the problem on exact location .I will rather say it is a network who has lost its purpose what we assigned initially and finding the actual reason where the network lost its purpose and recovering the ultimate purpose of network is called Troubleshooting.
Troubleshooting ,its a never ending topic and always getting bigger and bigger ,but we like challenges and if we do troubleshooting than the deeper we go the deeper we fall in love with troubleshooting.
Today ,i will start with Basic Troubleshooting Methodology:
1.What is the Problem?--Gathering the Facts
2.Where is the Problem?--looking for the clues
1st ---Looking for the quick confession or obvious clues
2nd---Scavenger Hunt for clues
3rd----Prepping for Deeper Troubleshooting
What is happening ?-------->Understanding the problem can be the biggest step
Connectivity Loss?
---Packet loss?
----Latency ?
----Network Management System shows Issue
What is Normal? ---Is everything is normal --proper way configured or not!!
What has changed??---
---Did someone change something?
---Did the network itself change something?
1st Methodology:
Looking for the quick confession or obvious clues:
Pings, Trace routes,show ip route
---Show ip route
---Ping
---Extended ping
---Traceroute
---Extendable traceroute
---IP SLA & Application Performance
After using the above commands we will get some clues ,let those evidence guide you.
2nd Methodology:
----Status of Routing peer Relationship
----IP interface status
---Interface issues
----Interface Summary Information
----Device specific Issues
----Application Issues
For peer relationship use the following commands
1.show tcp(check the Datagrams)
2.show tcp brief(check the ports --like for LDP-646, BGP-179,MSDP-639 IS everything correct)
3.For BGP use cmd- show ip bgp summary(Note the InQ and OutQ up and down status)
4.Eigrp use cmd-- show ip eigrp neighbor(Check on Uptime and also Quick count for the packets update,query and reply).
5.OSPF use cmd -- show ip ospf neighbor (check DR/BDR status )
--show ip ospf neighbor detail | include up for
Now check on Interface IP status
Interfaces with Ip addresses assigned ---Are they UP/UP status?
cmd use-- show ip interface brief
--- show interface | include drops
--- show interface | include errors
------show interface summary(look on RXBS,RXPS,TXBS,TXPS)
3rd Methodology:
Prepping for deeper troubleshooting
Commands:
----Load-interval 30 (configured on interested interface)
----clear counters
----Ensure logging
----Clear log
Underground Suspicious Router Use:::
commands:
Show proc cpu
show ip traffic (clear ip traffic)
Show log (clear Log)
Clear Counters
Any query please feel free to contact me.Thank you .Next coming on --Troubleshooting And Repairing
