|
|
|
|
|
|
|
SNMP Viewer
The SNMP Viewer lets you quickly view the status of interfaces on an SNMP-manageable device.
In the map, a device icon that has a star on the upper-right corner is an SNMP-manageable device. This star changes to a magenta color when an SNMP trap is received.
To view interfaces for an SNMP manageable device:
The SNMP Viewer displays an icon for each interface on the device, as shown in the following example.
This view shows all interfaces on the selected device, and for each interface, shows its type and status. Colors indicate the status of an interface:
Green the interface is up and running Red the interface is down Gray the interface is not configured To view detailed SNMP data for an interface:
The MIB Viewer shows current data for that interface.
Right-click the System device icon (first icon on the left) to open the System information section of the MIB tree.
To graph any of the SNMP counters:
Select one or more counters to graph, then click OK.
The SNMP Graph Utility appears and begins graphing the selected SNMP object. You can select multiple objects to appear on the same graph.
To view other SNMP objects for the selected device:
ARP Table - see "ARP Table"
Address Table - see "Address Table"
Route Table - see "Route Table"
Interface Table - see "Interface Table"
To view SNMP objects for other devices, you can:
- From the Tools menu, select SNMP Viewer, then enter the information described below.
- In the SNMP Viewer, from the File menu, select New, then enter the information described below.
- Right-click a device in the map, then select SNMP View from the pop-up menu. The SNMP Viewer shows the interfaces for that device.
Device SNMP Info
You can use the SNMP Viewer tool to view and monitor SNMP objects for a device. There are three ways that you can select the device for which you want to see SNMP information:
- From the Tools menu, select SNMP Viewer, then enter the information described below.
- In the SNMP Viewer, from the File menu, select New, then enter the information described below.
- Right-click a device in the map, then select SNMP View from the pop-up menu. The SNMP Viewer shows the interfaces for that device.
Host Name. Enter the host name or IP address of a device.
Community. This is the password used for SNMP read permission for this device. (Note: You can set the Read Community for all maps and all devices by using the Replace SNMP Community feature.)
Timeout. Enter the timeout. A value of 500 or greater is treated as milliseconds; less than 500 as seconds. If a device does not respond to the SNMP request within this time, the request times out.
MIB Viewer
To show the SNMP MIB objects for an interface, right-click an interface icon (in the SNMP Viewer), then select View MIB from the popup menu. The MIB Viewer shows current data for that interface.
The MIB Viewer also lets you view any SNMP object in a device's Management Information Base (MIB). You can use the viewer to "walk" the MIB tree, viewing SNMP objects for any of the interfaces on a device (all interfaces on the device are listed in the interfaces category of the MIB).
To monitor an SNMP Object:
From the MIB Viewer, you can select an SNMP object to monitor: right-click on an SNMP counter, then select Monitor. The SNMP Graph Utility appears and begins graphing the selected SNMP object. You can select multiple objects to appear on the same graph.
To get the object identifier for an SNMP Object:
From the MIB Viewer, double-click an SNMP object. The object identifier and its value are shown in a dialog box.
ARP Table
From the Table menu, select ARP Table.
The Address Resolution Protocol (ARP) Table maps IP addresses to physical hardware addresses. When a host or router on your network needs to send data to another device in the network, it can use the ARP Table to find the device's physical address.
The ARP Table is maintained dynamically by ARP, the protocol. For example, if your router receives data destined for a device with IP address 156.21.50.5, and it does not have this IP address in its ARP Table, the router broadcasts the IP address (via ARP) to machines in the local network. The IP owner replies (also via ARP) with its physical address; all other IP addresses ignore the request. When the router receives the reply, it saves the IP address and physical address pair in a cache for successive lookups - this cache is the ARP Table.
The columns in the ARP Table show the following information:
Index: A unique value that identifies the interface in the MIB's ifTable (same as ifIndex).
Address: The IP Address of a device in the local network; for example 156.21.50.5
Physical Address: The physical hardware address associated with the IP address. For Ethernet network adapters, the physical address is assigned by the manufacturer and looks like: 006080716fc0
Type: The media type of the physical device.
See RFC 1213 and 1156 for complete descriptions of all objects.
Address Table
From the Table menu, select Address Table.
The IP Address Table shows the IP addressing and subnet addressing information for your network. Subnet addressing segments the IP address into a network portion, which identifies the network and sub-network, and a local portion, which identifies the device or interface. This segmenting is accomplished by specifying a network Mask.
The columns in the Address Table show the following information:
Address: The IP address to which this entry's addressing information pertains.
Index: A unique value that identifies the interface in the MIB's ifTable (same as ifIndex).
Mask: The subnet mask associated with the IP address of this entry. The value of the mask is an IP address with all the network bits set to 1 and all the host bits set to 0.
Bcast: The value of the least-significant bit in the IP broadcast address used for sending datagrams on the (logical) interface associated with the IP address of this entry. For example, when the Internet standard all-ones broadcast address is used, the value will be 1.
ReasmMazSize: The size of the largest IP datagram that can be reassembled from incoming IP datagram fragments.
See RFC 1213 and 1156 for complete descriptions of all objects.
Route Table
From the Table menu, select Route Table.
IP routing is the method by which a router chooses a path over which to send data (packets). A device can send data directly to another device as long as the two devices are in the same local (physical) network. When a device sends data to a device on another network, it must send it through a router.
A router looks at the destination address of the packet and checks its Route Table to determine where to send the packet next. The Route Table contains an entry for each route presently known to the router.
The columns in the Route Table show the following information:
Dest Address. The destination IP address of this route. An entry with a value of 0.0.0.0 is considered a default route. Multiple such default routes can appear in the table, but access to such multiple entries is dependent on the table-access mechanisms defined by the network management protocol in use.
Index. The index value, which uniquely identifies the local interface through which the next hop of this route should be reached.
Metric1 - Metric4. Metric1 is the primary routing metric for this route; Metrics 2 through 4 are alternate routing metrics. The semantics of these metrics are determined by the routing-protocol specified in the route's Proto value. If a metric is not used, its value should be set to -1.
NextHopAddr. The Next Hop Address shows the IP address of the next hop of this route.
Type. The type or route: (1) = other, none of the following; (2) = invalid, an invalidated route; (3) = direct, route to a directly connected (sub-)network; (4) = remote, route to a non-local host/network/sub-network.
Proto. The IP routing protocol via which this route was learned. (1) = other, none of the following ; (2) = local, non-protocol information, e.g., manually configured entries; (3) = netmgmt, set via a network management protocol; (4) = .icmp, obtained via ICMP; the rest are gateway routing protocols: (5) = egp; (6) = ggp; (7) = hello; (8) = rip; (9) = is-is; (10) = es- is; (11) = CiscoIgrp; (12) = bbnSpfIgp; (13) = oigp
Inclusion of values for gateway routing protocols is not intended to imply that hosts should support those protocols.
Age. The number of seconds since this route was last updated or otherwise determined to be correct. Note that to determine whether the Age is "too old", you need to know what is appropriate for the routing protocol used.
Mask. The subnet mask associated with the IP address of this entry. The value of the mask is an IP address with all the network bits set to 1 and all the host bits set to 0.
Metric5. Alternate routing metric.
Info. Routing protocol information; set to zero by default.
See RFC 1213 and 1156 for complete descriptions of all objects.
Interface Table
From the Table menu, select Interface Table.
The Interface Table lists the network interfaces (regardless of their current state) on which the selected device can send/receive IP datagrams. For each interface, the table shows descriptive data and current values of the counters (for example, inOctets, outOctets) used to assess the performance of the interface.
The columns in the Interface Table show the following information:
Index: A unique value that identifies the interface in the MIB's ifTable (same as ifIndex).
Description: Can include the name of the manufacturer, the product name and the version of the hardware interface.
Interface Type: The type of interface, distinguished according to the physical/link/network protocol(s) immediately "below" IP in the protocol stack.
Address: The interface's address at the protocol layer immediately "below" IP in the protocol stack. For interfaces that do not have such an address (e.g., a serial line), this object should contain an octet string of zero length.
Admin Status: The desired state of the interface: Up - ready to pass packets; Down; or Testing - in some testing state.
Operator Status: The current state of the interface. Up - ready to pass packets; Down; or Testing - in some testing state.
MTU: The size of the largest IP datagram that can be sent/received on the interface, specified in octets.
Speed: An estimate of the interface's current bandwidth in bits per second. For interfaces that do not vary in bandwidth, or for those where no accurate estimation can be made, this object should contain the nominal bandwidth.
Last Change: The value of sysUpTime at the time the interface entered its current operational state. If the current state was entered prior to the last re-initialization of the local network management subsystem, then this object contains a zero value.
InUCastPkts: The number of (subnet) unicast packets delivered to a higher-layer protocol.
InUNCastPkts: The number of non-unicast (i.e., subnet broadcast or subnet multicast) packets delivered to a higher-layer protocol.
InErrors: The number of inbound packets that contained errors preventing them from being deliverable to a higher-layer protocol.
InDiscards: The number of inbound packets which were chosen to be discarded even though no errors had been detected to prevent their being deliverable to a higher-layer protocol. One possible reason for discarding such a packet could be to free up buffer space.
Unknown Protos: The number of packets received via the interface which were discarded because of an unknown or unsupported protocol.
OutUCastPkts: The total number of packets that higher-level protocols requested be transmitted to a subnet-unicast address, including those that were discarded or not sent.
OutNUCastPkts: The total number of packets that higher-level protocols requested be transmitted to a non-unicast (i.e., a subnet broadcast or subnet multicast) address, including those that were discarded or not sent.
OutErrors: The number of outbound packets that could not be transmitted because of errors.
OutDiscards: The number of outbound packets which were chosen to be discarded even though no errors had been detected to prevent their being transmitted. One possible reason for discarding such a packet could be to free up buffer space.
InOctets: The total number of octets received on the interface, including framing characters.
OutOctets: The total number of octets transmitted out of the interface, including framing characters.
See RFC 1213 and 1156 for complete descriptions of all objects
 Ipswitch, Inc. http://www.ipswitch.com |
| |
|
|
|
| ©Ipswitch 2001 | |||
