The show controllers Command

The show controllers command displays information on all of the router's controllers. However, you can specify the type of controller so that only the information on that particular controller is displayed. Depending on the router you work with, it may have BRI, CBus, E1, Ethernet, FastEthernet, FDDI, Lex, MCI, PCBus, serial, T1, T3, Token, or VG-Anylan controllers. This command displays a variety of data such as firmware versions, memory management, and error counters for each controller's interface card(s). The displayed output may seem overwhelming; the reason is that a large portion of the displayed output comprises proprietary (and in some cases obsolete and irrelevant) information. However, in each set of output there are pieces of information that can be extremely useful for troubleshooting. For instance, the output of the show controllers ethernet command displays the media type each Ethernet interface is configured for. This section (in accordance with the CIT student book) will examine certain components of the show controllers token output (see Example 3-5 for a sample of this command's output) that can be useful for troubleshooting purposes. Example 3-5 The show controllers token Command Output

A_StubR# show controllers token

TR Unit 0 is board 0 - ring 0 state 3, dev blk: 0x1D2EBC, mailbox: 0x2100010, sca: 0x2010000

current address: 0000.3080.6f40, burned in address: 0000.3080.6f40 current TX ptr: 0xBA8, current RX ptr: 0x800 Last Ring Status: none Stats: soft:0/0, hard:0/0, sig loss:0/0

tx beacon: 0/0, wire fault 0/0, recovery: 0/0 only station: 0/0, remote removal: 0/0 Bridge: local 3330, bnum 1, target 3583

max_hops 7, target idb: 0x0, not local Interface failures: 0 -- Bkgnd Ints: 0 TX shorts 0, TX giants 0 Monitor state: (active)

flags 0xC0, state 0x0, test 0x0, code 0x0, reason 0x0 f/w ver: 1.0, chip f/w: '000000.ME311001, [bridge capable] SMT versions: 1.01 kernel, 4.02 fastmac ring mode: F00, internal enables: SRB REM RPS CRS/NetMgr internal functional: 0000011A (0000011A), group: 00000000 (00000000)

Example 3-5 The show controllers token Command Output (Continued)

if_state: 1, ints: 0/0, ghosts

: 0/0, bad_states: 0/0

t2m fifo purges: 0/0

t2m fifo current: 0, t2m fifo

max:

0/0, proto_errs

0/0

ring: 3330, bridge num: 1, target:

3583, max hops:

7

Packet counts:

receive total: 298/6197, small:

298/6197, large

0/0

runts: 0/0, giants:

0/0

local: 298/6197, bridged

: 0/0, promis: 0/0

bad rif: 0/0, multiframe:

0/0

ring num mismatch 0/0, spanning

violations 0

transmit total: 1/25, small:

1/25, large 0/0

runts: 0/0, giants:

0/0

, errors 0/0

bad fs: 0/0, bad ac: 0

congested: 0/0, not present: 0/0

Unexpected interrupts: 0/0, last

unexp. int: 0

Internal controller counts:

line errors: 0/0, internal

errors: 0/0

burst errors: 0/0, ari/fci

errors: 0/0

abort errors: 0/0, lost frame:

0/0

copy errors: 0/0, rcvr congestion: 0/0

token errors: 0/0, frequency errors: 0/0

dma bus errors: -/-, dma parity

errors: -/-

Internal controller smt state:

Adapter MAC: 0000.3080.

6f40

, Physical drop:

00000000

NAUN Address: 0000.a6e0.

11a6

, NAUN drop:

00000000

Last source: 0000.a6e0.

11a6

, Last poll:

0000

3080

6f40

Last MVID: 0006,

Last attn code:

0006

Txmit priority: 0006,

Auth Class:

7FFF

Monitor Error: 0000,

Interface Errors:

FFFF

Correlator: 0000,

Soft Error Timer:

00C8

Local Ring: 0000,

Ring Status:

0000

Beacon rcv type: 0000,

Beacon txmit type:

0000

Beacon type: 0000,

Beacon NAUN:

0000

a6e0

11a6

As you can see, the show controller token command also displays the MAC address and bia of the Token Ring interface(s). Now let us examine some selected pieces of the output from Example 3-5, one at a time.

The show controller token Command Section 1

tx beacon: 0/0, wire fault 0/0, recovery: 0/0 only station: 0/0, remote removal: 0/0 Bridge: local 3330, bnum 1, target 3583

max_hops 7, target idb: 0x0, not local Interface failures: 0 -- Bkgnd Ints: 0 TX shorts 0, TX giants 0 Monitor state: (active)

In the preceding lines, you can see that certain parameters such as soft, hard, and sig loss are displayed with a number/number. The number before the slash—for example soft (errors)—counts the number of errors since the last time the show controllers token was executed. The number after the slash counts the total number of errors (since the counter was cleared) minus the number before the slash. On the following two lines, the number of transmitted beacons, wire faults, recoveries, the only station (on the ring) conditions, and the number of times this node was remotely removed from the ring by a management application are also displayed. The following line informs you that the Token Ring interface is configured as being connected to the local ring number 3330 and is connected to the target ring number 3583 via bridge number 1 (which this router is configured to act as). Next, the number of interface failures and background initializations, transmitted shorts (runts) and giants, and the monitor state are displayed.

As a review point, it is worthwhile mentioning that stations on a Token Ring transmit beacon frames as a Token Ring fault detection/repair mechanism whenever they experience network problems such as wire fault and signal loss.

The show controller token Command Section 2

Packet counts:

receive total: 298/6197, small: 298/6197, large 0/0 runts: 0/0, giants: 0/0

local: 298/6197, bridged: 0/0, promis: 0/0 bad rif: 0/0, multiframe: 0/0 ring num mismatch 0/0, spanning violations 0 transmit total: 1/25, small: 1/25, large 0/0 runts: 0/0, giants: 0/0, errors 0/0

In the preceding lines you can see that several different packet counts are displayed. Notice that the ring number mismatch and spanning tree violations counters could be significant for troubleshooting purposes. For instance, if the value for the ring num mismatch is nonzero, you have evidence that this device and other devices refer to the same ring with different ring numbers. As a part of your action, you must discover which devices disagree about the ring number and fix the misconfigured device(s).

The show controller token Command Section 3

Internal controller counts:

line errors: 0/0, internal errors: burst errors:

0/0, ari/fci errors: abort errors: 0/0, lost frame: 0/0 copy errors: 0/0, rcvr congestion: token errors: 0/0, frequency errors: 0/0 dma bus errors: -/-, dma parity errors: -/-

Internal controller smt state:

Adapter MAC: NAUN Address: Last source: Last MVID: Txmit priority:

0000.3080.6f40,

0000.a6e0.11a6,

0000.a6e0.11a6,

0006,

0006,

Physical drop: NAUN drop: Last poll: Last attn code: Auth Class:

00000000 00000000

000.3080.6f40

0006

7FFF

Monitor Error: 0000

Correlator: 0000

Local Ring: 0000

Beacon rcv type: 0000

Beacon type: 0000

Interface Errors: FFFF Soft Error Timer: 00C8 Ring Status: 0000

Beacon txmit type: 0000 Beacon NAUN: 0000.a6e0.11a6

The preceding information is provided by the controller chipset. The top portion of this section reports the soft errors this station has experienced. The line errors, burst errors, and receive-congested errors are among the most common errors in tokenring networks. The line error counter increments as CRC check failures occur. The burst error counters report on signaling errors seen (these are usually due to noise and/or crosstalk). The receive-congested error counter tells you if the station has had difficulty keeping up with processing of the received traffic. In cases where these counters are nonzero and require investigation, use a network monitor or protocol analyzer to capture traffic and investigate which stations are acting up or to find out if you need to test the media or tokenring hardware and cabling.

Token Ring Soft Errors

The Token Ring soft errors are divided into two classes: isolating soft errors and non-isolating soft errors. Isolating soft errors are those that are caused by the local station, its NAUN (Nearest Active Upstream Neighbor), or devices/medium in between the two. Notice that the lower part from "The show controller token Command Section 3" output informs you of the local station's and NAUN's MAC addresses. The non-isolating soft errors are not necessarily caused by the local station or its NAUN; these errors can be caused by device(s) anywhere in the ring. Tables 3-3 and 3-4 list the group of soft errors belonging to each class with a short description of each error.

Table 3-3 Token Ring Isolating Soft Errors

Line error

CRC errors

Internal error

The number of recoverable internal station

errors (station is in a marginal state).

Burst error

Incorrect incoming signal (usually due to cross-

talk or noise).

ARI/FCI error

More than one "active monitor present" or

"standby monitor present" frame was received,

where the address was recognized and the

frame copied bits equal zero. Indicates a

problem with the neighbor notification (ring

poll). This is usually caused by NAUN.

Abort error

Errors during frame transmission.

Table 3-4 Token Ring Non-Isolating Soft Errors

Lost frame

Sent frame never returned to the sender.

Copy error

Frame destined for the station was received

with the address-recognized bit set. This is due

to duplicate MAC addresses.

Receive congested

The station has been unable to copy all the data

sent to it. The station could be congested

because another station sends it too much data.

Token error

Generated by Active Monitor and is a valid

action, unless it happens too often.

Frequency error

Error in the frequency of the incoming signal.

The Active Monitor is responsible for

compensating for this. You may want to replace

the Active Monitor by temporarily removing it

from the ring.

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