Add an Aruba 2930F in a Cisco enviroment

[ovigara]

Hello, good afternoon. I´m new here, please to meet all of you.

Good afternoon.

I have to add an Aruba 2930F switch to a Cisco switch infrastructure. There is a Cisco stack that routes and the rest of the switches send everything to that stack, they do not route. There are several vlans (1,2,10 and 255). The switches are under vlan 255. Each Vlan has a scope of the DHCP server. I have configured the vlans in aruba but I cannot get a team to take Ip correctly by clicking it on any of the interfaces. I have configured the ip-helpder values of each vlan but I click a laptop to those jacks and it does not take IP. The native vlan on the cisco is 1 (wired computer vlan) on subnet 172.17.1.0. I have configured port 48 as trunk and from a computer connected to the cisco access to the management ip of aruba (172.17.255.249), but I cannot get a connection between computers. The default GT in Aruba is the IP of the Cisco stack (172.17.255.254). Could it be an error with the assignment (tag-untag) of the ports to the corresponding vlans?

Thanks a lot for your help.

[parnassus]

Hi! an essential requirement when interconnecting two switches by means of a point-to-point link (physical, in case of single link or logical, in case of ports aggregation) is that VLAN taggings match on involved peers' ports: VLAN tagging on Aruba 2930F port should match VLAN tagging on Cisco.

Are you able to post how is configured Cisco interface connected to Aruba 2930F from the VLAN tagging standpoint?

Are you able to post how is configured Aruba 2930F port connected to Cisco from the VLAN tagging standpoint? use the ArubaOS-Switch CLI command show vlan port <port-id> detail to gather such details.

Please refer to this presentation to understand what I mean (pay attention to jargon differences between Cisco and Aruba: Aruba port trunks are links aggregations and Cisco trunks are simply Aruba VLAN tagging).

[ovigara]

Good morning. First of all thanks a lot for your help.

In the aruba swich i have created a trunk port in the interfaz number 48:

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Aruba-2930F-48G-PoEP-4SFPP# show vlan ports Trk1 detail

Status and Counters - VLAN Information - for ports Trk1

VLAN ID Name | Status Voice Jumbo Mode
------- -------------------- + ---------- ----- ----- --------
255 Gestao | Port-based No No Untagged

_________________________________________________________________

I try to put like the Cisco port (where is connected to) is configured: In this case, another trunk linked to the Vlan 255 in the port Gi3/0/3

__________________________________________________________________________________________

SWESBIO01>show vlan id 255

VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
255 Gestao active Gi1/0/18, Gi1/0/43, Gi1/0/44
Gi2/0/31, Gi2/0/38, Gi2/0/42
Gi2/0/43, Gi2/0/44, Gi2/0/47
Gi3/0/3, Gi3/0/27, Gi3/0/44
Gi3/0/46, Gi3/0/49

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
255 enet 100255 1500 - - - - - 0 0

________________________________________________________________________________________________________

I have connection between the switches via the trunk ports, but i have problems with the DHCP clients/ip helper IPs. I can ping to the DHCP Server from the aruba (those servers are connected in machines connected to the Cisco), but if i connect a laptop in one interface does not take an IP. I have one scope per vlan.

I dont have the routing enable in the Aruba, i have the IP of the Cisco Stack as the default gateway (like other CIscos that i have in the network out of the main stack). I have read that i need to put the 2930F to use routing to can use the ip-helper  values... Take a look to my ip-helpder values inside the Aruba:

________________________________________________________________________________________________

Aruba-2930F-48G-PoEP-4SFPP# show ip helper-address

IP Helper Addresses

VLAN: 1
IP Helper Address
-----------------
172.17.1.254

VLAN: 2
IP Helper Address
-----------------
172.17.2.254

VLAN: 10
IP Helper Address
-----------------
172.17.10.254

VLAN: 21
IP Helper Address
-----------------
172.17.21.254

VLAN: 200
IP Helper Address
-----------------

VLAN: 255
IP Helper Address
-----------------
172.17.255.254

________________________________________________________________

My static routes are those ones:

Aruba-2930F-48G-PoEP-4SFPP# show ip route

IP Route Entries

Destination Gateway VLAN Type Sub-Type Metric Dist.
------------------ --------------- ---- --------- ---------- ---------- -----
0.0.0.0/0 172.17.255.254 255 static 250 1
127.0.0.0/8 reject static 0 0
127.0.0.1/32 lo0 connected 1 0
172.17.0.0/16 172.17.255.254 255 static 1 1
172.17.255.0/24 Gestao 255 connected 1 0

A test, from the aruba ssh conection, i can ping to the ip-helper ip of the vlan 21 (that is on the Cisco Stack)

Aruba-2930F-48G-PoEP-4SFPP# ping 172.17.21.254
172.17.21.254 is alive, time = 2 ms

I think that perhaps i have a conf error in the vlan assignement on the aruba ports (tagged, untagged,...) or a route conf error.

Again, thank you very much for your help and knowledge.

Oliver.

[parnassus · Accepted solution]

Hi Oliver, one step at time.

First you have to fix the very first error...you know I wrote you "pay attention to jargon differences between Cisco and Aruba: Aruba port trunks are links aggregations and Cisco trunks are simply Aruba VLAN tagging"...isn't it? that's exactly what happened on your Aruba configuration (you're probably a Cisco guy)...you indeed used the "Trk"="Trunk" guessing that its meaning is the same as of Cisco (Trunk=More VLANs on a interface)...it's not.

Trk=Port Trunking in HP/HPE/Aruba jargon means "Port Aggregation" which is the "EtherChannel" in Cisco jargon. So working with HP/Cisco is easy to mix two very different features.

You haven't EtherChannel (Port Group) on your Cisco side connected to the Aruba, haven't you [*]? so let we fix that first.

You have first to delete Trk1 (it's member port will return to be untagged member of VLAN 1 Default) and then (re)confiugure the single port with proper tagging.

Aruba 2930F port 48 <----> interface 3/0/3 Cisco "SWESBIO01"

With:

vlan 255 (enter the VLAN 255 context)

untagged 48 (configure port 48 to be untagged into VLAN id of your actual VLAN context)

show vlan port 48 detail (to verify the VLANs tagging membership)

Once done that we can start troubleshooting the DHCP part.

[*] Another approach would be: if you have a three members Cisco Stack (Onl if you're dealing with a VSS or a Virtual Switch logical entity) then the best thing you could do is to create a three member ports EtherChannel (Ports Group) with LACP and do the same on the Aruba side...this time the Aruba Trk1 will be justified (trk1 made of three ports with LACP as control protocol). Doing thing that way any stack member you will lose Cisco side the logical interface between Aruba and Cisco will stay up and running (because it's resilient having three member links, each one terminating into a different Cisco member). Clearly if the Aruba switch goes down...end of the game no matter the number of links you have between it and the Cisco stack.

[ovigara]

You´re great. It´s works right now!