RE: What are the network monitoring tools? Like what t...
Testing basic network connectivity > ping s /If ping successful > upper layer problem > snoop o & snoop i to capture and read the events snoop x > to display packet contents snoop v > verboseSNMP traps Element ManagerUnsuccessful ping > Error Message1) Unknown host check the name service > nslookup set type NS [Troubleshooting remote server problem] foo.edu [Directly query the authoritative servers returned by NS query] set type ANY [] returns all records about a host]2) Network Unreachable > Routing Error - Check if valid route exits for destination > netstat nr | grep 128.8.0 - If no problem with routing entry use traceroute- Check if the default route exists > netstat nr | grep def- If default route/routing entry is missing and the system uses static routing > route add - If dynamic routing is used make sure the gated daemon is running > ps cat /etc/gated.pid - check the RIP updated sent and received >ripquery -1[version] n[IP in numeric] r[use RIP REQ instead of RIP POLL] 3) No Answer > Problem in lower layers test on local interface and routing- ifconfig le0 interface up & running bad subnet mask [hosts can reach other hosts on local subnet and remote hosts on distant networks BUT cannot reach hosts on other local subnets] Improper Broadcast address Bad IP address [If network ID incorrect every ping fails OR host part incorrect]- arp a [display arp table] if there are two hosts with same IP - arp d [delete an entry in arp table] - arp s [add an entry in ARP table]- Connection to a LAN is unreliable > netstat i gives Network Interface MTU Destination Network hostname/IP Address Ipkts Ierrs Opkts Oerrs Collis Queue- Ierrs/Oerrs 100 is high saturated network or local host is overloaded. Collision rate Collis/Opkts*100 > 5 is high subdivide the network using Ethernet switch- Queue filed increasing no. of packets that cannot be transmitted bad NIC/cable
RE: What are the network monitoring tools? Like what t...
Network monitoring tools are different from network tools like ping tracert etc. Network monitoring tools are usually software we need to install and setup in our workstation or server to monitor the performance of the network. Some popular network tools are Cacti Nagios Whats Up gold. It also comes up with network tools like ping tracert etc to trouble shoot if ever there are alerts on our network or we need to discover something on our network.
