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Author Topic: enabling LLDP in Linksys / Cisco small business switches ( SPS and SRW) series  (Read 6382 times)

shadowcaster

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I got my hands on Linksys SPS224G4 switch, which is now branded as Cisco Small Business Switch. This howto apply to both SPS and SRW series of switches, as far as I know.
The root of the "problem" is that while this switches can do discovery protocol (LLDP), they got no CLI command to enable and manage LLDP. And this is when SNMP steps in!

To make long story short - I was browsing forums for any possible clue and found cisco small business snmp mibs archive! (there is no link in small business downloads)

Here it is:

https://www.myciscocommunity.com/docs/DOC-12539
and here is link
https://www.myciscocommunity.com/servlet/JiveServlet/downloadBody/12539-102-2-21519/SRW_MIB_2009.zip

and that was it! Now I was aware wnat snmp oids to set in order to enable lldp on my SPS224G4:


First:

snmpwalk -v2c -c <community> <ip> 1.3.6.1.4.1.3955.89.110.1.1.1.0

CISCOSB-LLDP-MIB::rlLldpEnabled.0 = INTEGER: false(2)

snmpset -v2c -c <community> <ip> 1.3.6.1.4.1.3955.89.110.1.1.1.0 i 1

CISCOSB-LLDP-MIB::rlLldpEnabled.0 = INTEGER: true(1)

 

Now, let's check port admin status:

snmpwalk -v2c -c <community> <ip> 1.0.8802.1.1.2.1.1.6.1.2

LLDP-MIB::lldpPortConfigAdminStatus.1 = INTEGER: txAndRx(3)
LLDP-MIB::lldpPortConfigAdminStatus.2 = INTEGER: txAndRx(3)
LLDP-MIB::lldpPortConfigAdminStatus.3 = INTEGER: txAndRx(3)
<cut>

and let's configure switch to send come TLVs

check first:

snmpwalk -v2c -c <community> <ip>  1.0.8802.1.1.2.1.1.6.1.4

LLDP-MIB::lldpPortConfigTLVsTxEnable.1 = BITS: 00
LLDP-MIB::lldpPortConfigTLVsTxEnable.2 = BITS: 00
LLDP-MIB::lldpPortConfigTLVsTxEnable.3 = BITS: 00
<cut>

and now set to some reasonable parameters:

snmpset -v2c -c <community> <ip>  1.0.8802.1.1.2.1.1.6.1.4.<portnumer> x F0

LLDP-MIB::lldpPortConfigTLVsTxEnable.<portnumer> = BITS: F0 portDesc(0) sysName(1) sysDesc(2) sysCap(3)
repeat for every port needed.
 

Now check other connected devices - they should see some LLDP neighbors!

like this:

snmpwalk -v2c -c <community> <neighbor_ip>  1.0.8802.1.1.2.1.4.1.1

LLDP-MIB::lldpRemChassisIdSubtype.41429900.1.1 = INTEGER: macAddress(4)
LLDP-MIB::lldpRemChassisId.41429900.1.1 = Hex-STRING: 00 22 6B 22 68 49
LLDP-MIB::lldpRemPortIdSubtype.41429900.1.1 = INTEGER: interfaceName(5)
LLDP-MIB::lldpRemPortId.41429900.1.1 = STRING: "g2"
LLDP-MIB::lldpRemPortDesc.41429900.1.1 = STRING: Ethernet Interface
LLDP-MIB::lldpRemSysName.41429900.1.1 = STRING:
LLDP-MIB::lldpRemSysDesc.41429900.1.1 = STRING: 24-port 10/100 + 4-Port Gigabit Switch with CLI and WebView
LLDP-MIB::lldpRemSysCapSupported.41429900.1.1 = BITS: 20 00 00 00 bridge(2)
LLDP-MIB::lldpRemSysCapEnabled.41429900.1.1 = BITS: 20 00 00 00 bridge(2)



now you can use your favorite network discovery software (NeDi!) to build automatic network topology and make auto network discovery!

rickli

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Sounds good. Especially something that will really get interesting once SNMPv3 is implemented (which will also enable set operations as I never wanted this for v2)...
Please consider Other-Invoices on your NeDi installation for an annual contribution, tx!
-Remo