871W: Wi-fi to Wi-fi unreliable

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I have a laptop on the wifi. It can connect to internet no problem. It
can connect to almost every host on the wired LAN without problem.

There is an IPMI destination on the wired LAN which is sometimes
accessible, sometimes not. (sometimes I can just start the GUI for
server monitoring, and within a few minutes it will be able to connect,
after which there is no problem - this never happens on the wired LAN
portion). During failed attempts, the wi-fi device does get an ARP
resolution for the IPMI destination.

Now howver, I try to ping or SSH to another wi-fi device (a phone) and
it fails royally.  I can telnet to a wired server from the laptop, and
that server has no problem pinging or SSH to the phone.

So wi-fi to LAN seems to work.
LAN to Wi-Fi seems to work.
But Wi-fi to wi-fi seems to be a problem.

Is this common ? What should I look at in the config ?

While I am at it, for such a router, what would be the best way to run
wireshark to scan all of the wi-fi traffic ? Can I do a port monitor on
the BVI10 interface ?

Re: 871W: Wi-fi to Wi-fi unreliable
Bringing back an old (unsolved) thread.

I rebooted my Cisco 870 router today. And My iphone and laptop, both on
wireless were able to talk to each other when I tried right away and
both were able to contact the IPMI interface on the server (on ethernet).


I (now) know that this model's claim to support 5 VLANs is bogus
becauise it has 4 vlans hardcoded which you can't remove (so you can
only support 1 VLAN).

Is it possible that the 870 would have limits in the number of MAC
addresses it can know about either gobally, or on a per interface basis ?

(The IPMI port is on the same physical ethernet cable as the server's
main ethernet interface)

(IPMI is for system management and is active even when server is powered

The problem or two wireless devices not talking to each other seems
sporadic, same with wireless devices not able to reach the IPMI. But
from the wired etehernet I have no problem reaching any device, wired or

Re: 871W: Wi-fi to Wi-fi unreliable

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Cisco IOS Software, C870 Software (C870-ADVIPSERVICESK9-M), Version
12.4(15)T7, RELEASE SOFTWARE (fc3)
Cisco 877W (MPC8272) processor (revision 0x200) with 118784K/12288K
bytes of memory.

router#sh vlan-s

VLAN Name                             Status    Ports
---- -------------------------------- ---------
1    default                          active    Fa3
2    family                           active    Fa0, Fa1, Fa2
3    test                             active
16   VLAN0016                         active
1002 fddi-default                     act/unsup
1003 trcrf-default                    act/unsup
1004 fddinet-default                  act/unsup
1005 trbrf-default                    act/unsup

Nothing bogus there as far as I can see.

You do need a non-basic Feature Set. e.g. ADVIPSERVICES.

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There are very probably hardware limits in the switch as
there are in all switches. In the router bit, if bridging, the
forwarding database and the ARP table will be in software
and you will be limited only by system memory.
How many MACs have you got?

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I am not a wireless expert but I think you need to consider
doing a survey for interference.

Might be worth considering.

I would expect to see evidence of interference
in the "show dot11 int" output. e.g. Retries, switching
to low data rates, use of low data rates.

alt.internet.wireless has some good people and I have
posted this there too.

Re: 871W: Wi-fi to Wi-fi unreliable

bod43 wrote:
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I have:
router1#show version
Cisco IOS Software, C870 Software (C870-ADVSECURITYK9-M), Version
12.4(15)T9, RELEASE SOFTWARE (fc5)

System image file is "flash:c870-advsecurityk9-mz.124-15.T9.bin"

And it won't let me create more than one VLAN.

My switch has 2 vlans defined (on top of the useless default ones) and
is in vtp server mode.

Router doesn't accept vtp client and reverts to vtp transparent.
(because it can't handle the 2 extra vlans).

I tried once to go to the cisco site to find the advanced software but
it doesn't seem to want to let me download software for the 800 series
routers. I may try again.

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show mac on the router gives 12, but it lacks some. For instance it
doesn't show the mac address of the BRAS router at the other end of a
PPPoE interface.

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Sort of strange that after rebooting, connectivity between wi-fi devices
and between them and IPMI works fine.

Perhaps it may have limits on number of wi-fi devices. Since the reboot,
it has only known about two. When I have friend over, perhaps the
problem will re-occur.

Re: 871W: Wi-fi to Wi-fi unreliable

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#sh ver
Cisco IOS Software, C870 Software (C870-ADVIPSERVICESK9-M), Version 12.4(15)T11,

#sh vlan-switch

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Fa1, Fa2
2    SDSL                             active    Fa3
10   Telefonie                        active
1002 fddi-default                     act/unsup
1003 token-ring-default               act/unsup
1004 fddinet-default                  act/unsup
1005 trnet-default                    act/unsup

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1    enet  100001     1500  -      -      -        -    -        1002   1003
2    enet  100002     1500  -      -      -        -    -        0      0
10   enet  100010     1500  -      -      -        -    -        0      0
1002 fddi  101002     1500  -      -      -        -    -        1      1003
1003 tr    101003     1500  1005   0      -        -    srb      1      1002
1004 fdnet 101004     1500  -      -      1        ibm  -        0      0
1005 trnet 101005     1500  -      -      1        ibm  -        0      0

From running-conf:
interface FastEthernet0
 switchport trunk allowed vlan 1,3-4094
 switchport mode trunk
interface FastEthernet1
interface FastEthernet2
interface FastEthernet3
 switchport access vlan 2

#sh vtp status
VTP Version                     : 2
Configuration Revision          : 3
Maximum VLANs supported locally : 8
Number of existing VLANs        : 7

Re: 871W: Wi-fi to Wi-fi unreliable

Rob wrote:

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router1#show vtp status
VTP Version                     : 2
Configuration Revision          : 0
Maximum VLANs supported locally : 6
Number of existing VLANs        : 6

So with the default software version, you have 5 default VLANs which you
can't delete (vlan 1 and 4 strange ones), which leaves just 1 you can

Since I have the "crippled" version, I have to wonder what other
artificial restrictions exist on the unit.  When I purchased it, I
figured 6 VLANS was plenty. Didn't know 6 vlans really meant just 1.

Re: 871W: Wi-fi to Wi-fi unreliable

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I don't know why your model only allows 6 while mine allows 8.
I use 3 vlans and I would not have enough with 6 allowed either.

I agree with you that it sucks that you cannot delete those 4 fixed
vlans.  I don't use token ring and I never will.  I don't need a
token ring vlan.

Re: 871W: Wi-fi to Wi-fi unreliable

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It is, always has been, and always will be the Cisco way
to sell routers or whatever with a single set of
marketing blurb then to have different versions of
the software for different costs that offer various
subsets of the functionality.

It's no different for cars or Microsoft Windows or
any other complex product.

Maybe they should do it some other way but I bet that won't
happen any time soon. You need to check the features
you need against the documentation before purchase.
If you can't understand the documentation then you need
to hire someone who does.

My view is that the products are intended to be specified
by experienced professionals just as steel beams for
buildings might be. Complaining to a supplier
of construction materials that you didn't know what you
were doing when you ordered a hundred tons of steelwork
but got the wrong stuff will I would guess cut no ice at all.
It is the same here. Don't be fooled that an 800 series router
only costs a few hundred pounds, as I think you know
it has the same software features as a router that costs
hundreds or thousands of times as much.
The documentation for that $300 router extends to
thousands and thousands of pages (I have no estimate
now but 10 years ago when you could still get paper
manuals the set looked like about 10 telephone
directories and there are many times the number of
features now).

Good luck:)

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