Information Technology Reference
In-Depth Information
Troubleshooting the DHCP Relay Agent
The DHCP Relay Agent is not providing relay services for DHCP clients on a network
segment
Troubleshooting IP multicast
The IGMP router does not work correctly
Troubleshooting demand-dial routing
On-demand connection is not made automatically
Unable to make a demand-dial connection
Unable to reach locations beyond the calling router or answering router
Auto-static updates are not working
There are a number of utilities, including the most basic system event log, that are a part
of Windows Server 2003 and that should be included in any IT administrator's toolkit. These
can be very useful for diagnosing routing issues: ping, tracert, pathping, mrinfo, and tracing.
Ping
Ping is probably the most fundamental and well-known command for diagnosing routing and
connectivity issues. Ping hosts by IP address to determine whether they are active and reach-
able. Ping them by host name to verify that name resolution is working properly.
Most administrators should be familiar with the basic syntax:
> ping Destination
There are additional parameters available. A comprehensive
ping
syntax includes the
following:
> ping [-t] [-a] [-n
count
] [-l
size
] [-f] [-i
TTL
] [-w
timeout
]
[-R] [-S
srcaddr
] [-4] [-6] Destination
The parameters are described by typing
ping /?
at a command prompt:
-t
Pings the specified host until stopped; to see statistics and continue,
type Ctrl-Break; to stop type Ctrl-C.
-a
Resolves addresses to hostnames
-n
count
Specifies the number of echo requests to send
-l
size
Specifies the send buffer size
-f
Sets the Don't Fragment flag in packet (IPv4-only)
-i
TTL
Sets the time to live
-v
TOS
Sets the type of service (IPv4-only)
-r
count
Records the route for count hops (IPv4-only)
