Send netdisco-users mailing list submissions to
[email protected]
To subscribe or unsubscribe via the World Wide Web, visit
https://lists.sourceforge.net/lists/listinfo/netdisco-users
or, via email, send a message with subject or body 'help' to
[email protected]
You can reach the person managing the list at
[email protected]
When replying, please edit your Subject line so it is more specific
than "Re: Contents of netdisco-users digest..."
Today's Topics:
1. Re: ND2 strange node behaviour (Alan Buxey)
2. Re: ND2 strange node behaviour (Nikolaos Milas)
3. Re: ND2 strange node behaviour (Alan Buxey)
4. ND2 LLDP discovery on Juniper EX series switches (Cody Wood)
5. Re: ND2 strange node behaviour (Nikolaos Milas)
--- Begin Message ---
'I can confirm that this phenomenon happens to practically all our
switches: about 30 Cisco 2960/2950 of various types and a couple Cisco
SRW2024-K9 (SG300-28)'
Theres something else going on here then as the cam table should be pretty
stable. .. Unless your clients are literally losing connectivity. ... Some
spanning tree thing, l2 loop, flooding of table or such.... There's just the
air of something not right with the l2 space on those switches. ... and I'd be
against trying to showhorn some fix into a network management platform to hide
such problems
My €0.01
alan
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
--- End Message ---
--- Begin Message ---
On 30/5/2014 12:44 μμ, Alan Buxey wrote:
Some spanning tree thing, l2 loop, flooding of table or such....
There's just the air of something not right with the l2 space on those
switches.
Hi Alan,
Did you read Mark's comments? "Historically Cisco switches will not
always report a MAC on a port even while it has a node that is being
spoken to."
In any case, the ports to nodes are configured with:
switchport mode access
spanning-tree portfast
and they shouldn't cause issues with STP. There are no loops - switches
are in-line (no redundancy, I know), and the mac-address-table is rather
short. As I have documented on a direct mail to Oliver, here is -as an
example- what happens to one port on a Cisco 2960-24TT (a Lexmark net
printer is connected to port: Fast Ethernet 0/3):
csw-astr0#sh clock
11:23:24.570 EET Tue May 27 2014
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
1 0004.0092.aa9d DYNAMIC Fa0/3
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
1 0004.0092.aa9d DYNAMIC Fa0/3
csw-astr0#
csw-astr0#sh clock
11:24:04.836 EET Tue May 27 2014
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#sh clock
11:24:29.658 EET Tue May 27 2014
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
csw-astr0#
csw-astr0#show mac address-table | incl 0004.0092.aa9d
1 0004.0092.aa9d DYNAMIC Fa0/3
csw-astr0#
csw-astr0#sh clock
11:24:51.661 EET Tue May 27 2014
It MAY be device-dependent, but a solution for these cases should be
devised. Remember also that ND1 works differently and we never had such
issues with it.
I'd be against trying to showhorn some fix into a network management
platform to hide such problems
Me too, but it wouldn't hurt to test optional patches and features which
do not alter the basic platform. Or provide the option to work in ND1 mode.
All the best,
Nick
--- End Message ---
--- Begin Message ---
That client device seems to be on the default native vlan. Not using seperate
vlan for devices and mgnt? It may very well be a case of cam table exhaustion
if it's one big flat l2 network. Check switch resources and the SDM profile in
use on the switch.
Certainly having 'invisible' nodes on our Cisco devices is something we have
not seen here as such a thing would be broken behaviour and we'd be dealing
with TAC to get it fixed (!)
alan
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
--- End Message ---
--- Begin Message ---
I have just installed ND2 and it is up and running and discovering my cisco
switches fine. It can see the neighbors of each cisco switch via CDP.
However, when I discover a Juniper switch it outputs "neigh - CDP/LLDP not
enabled!" and lists no neighbors in the web interface. I've gone to the
switches and confirmed that LLDP is enabled and working correctly. From my
netdisco box, I can snmpwalk to an ex series switch and OID 1.0.8802.1.1.2.1
does show its neighbors. What am I missing?
Thanks,
Cody Wood
Systems Administrator, Network Operations
Southeastern Oklahoma State University
--- End Message ---
--- Begin Message ---
On 30/5/2014 1:44 μμ, Alan Buxey wrote:
That client device seems to be on the default native vlan. Not using
seperate vlan for devices and mgnt? It may very well be a case of cam
table exhaustion if it's one big flat l2 network. Check switch
resources and the SDM profile in use on the switch.
Thank you Alan for your advice.
Yes, we are not using a separate vlan for management. We have a
relatively small network and we are far from table exhaustion. All
switches are Layer 2. Routing is done by a Cisco 3825 with multiple
interfaces.
Some (attempted) troubleshooting -always for the same node:
csw-astr0#sh clock
23:12:58.425 EET Fri May 30 2014
csw-astr0#sh ip arp | incl 0004.0092.aa9d
Internet 195.251.202.16 12 0004.0092.aa9d ARPA Vlan1
So, the MAC address is in the arp table, but:
csw-astr0#sh mac-address-table address 0004.0092.aa9d
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
...it is not available in the mac-address-table. If we ping the
associated IP address:
csw-astr0#ping 195.251.202.16
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 195.251.202.16, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/9 ms
...then the mac address shows up in the mac-address-table:
csw-astr0#sh clock
23:13:26.603 EET Fri May 30 2014
csw-astr0#sh mac-address-table address 0004.0092.aa9d
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
1 0004.0092.aa9d DYNAMIC Fa0/3
Total Mac Addresses for this criterion: 1
...but after a few seconds, it is no more available:
csw-astr0#sh clock
23:13:45.167 EET Fri May 30 2014
csw-astr0#sh mac-address-table address 0004.0092.aa9d
Mac Address Table
-------------------------------------------
Vlan Mac Address Type Ports
---- ----------- -------- -----
Yet, there is no problem with table space:
csw-astr0#sh mac-address-table count
Mac Entries for Vlan 1:
---------------------------
Dynamic Address Count : 26
Static Address Count : 0
Total Mac Addresses : 26
Mac Entries for Vlan 100:
---------------------------
Dynamic Address Count : 4
Static Address Count : 0
Total Mac Addresses : 4
Total Mac Address Space Available: 7418
Also:
csw-astr0#show sdm prefer
The current template is "default" template.
The selected template optimizes the resources in
the switch to support this level of features for
0 routed interfaces and 255 VLANs.
number of unicast mac addresses: 8K
number of IPv4 IGMP groups: 0.25K
number of IPv4/MAC qos aces: 0
number of IPv4/MAC security aces: 0.25K
Indeed, if I do a "ping 195.251.202.16" (either on the switch or from
another box) and then I IMMEDIATELY force a macsuck in ND2, then the
node (since it has been included for a short while -a few seconds- in
the MAC table) appears in ND2.
But why the particular MAC address is getting removed from the
MAC-Address-table so quickly? Any ideas will be appreciated!
Thanks,
Nick
--- End Message ---
------------------------------------------------------------------------------
Time is money. Stop wasting it! Get your web API in 5 minutes.
www.restlet.com/download
http://p.sf.net/sfu/restlet
_______________________________________________
Netdisco mailing list - Digest Mode
[email protected]
https://lists.sourceforge.net/lists/listinfo/netdisco-users
