RDP not successful via Nexus FEX

[Ari Darmariyadi]

Hi All,

I'm in the middle of setting up Nexus 5548 with FEX NX2248 straight-through PortChannel and vPC connection, gateway from server hosts is Cisco 3750.

Here are the symptom:

- Ping between PC in same VLAN and different VLAN is successful.

- Ping from PC client to host in VPN cloud is successful

- RDP connection between PC in same VLAN within FEXs is successful.

- RDP connection between PC different VLAN within FEXs is not successful (failed).

- RDP from PC connected to Cisco 3750 to host at VPN cloud is successful

- RDP from PC connected to FEX to the same host in VPN CLOUD was not successful (failed)

I attached my setup and configurations, my suspect lies on the connection to layer 3 (3750), but I couldn't see anything wrong with it.

Appreciate if someone could point me where and what I suppose to check.

Thank you in advance.

Regards,

Ari

[Ari Darmariyadi]

Hi All,

Just want to share, after done a long troubleshooting session with Cisco TAC, there was a little progress.

Initially, even though PC Client is connected to N5K when ping to C3750 SVI if ping packet larger than 252 bytes, ping was not smoothly get replied from SVI, but after disabling DTP in C3750 trunk interface, ping smoothly get replied from SVI and through the C3750 to host in VPN cloud and RDP is successfully perform.

Things that left is when PC client connected to FEX, ping to SVI or host in VPN cloud when packet size larger than 252 still get packet loss, RDP also failed.

[Prashanth Krishnappa · Accepted solution]

I see your connection from 5548 to 3750 is at 1 Gig. 1 Gig is not supported on 5548 at this time but parser lets you configure it. Since your 3750-X has 10 Gig interfaces as well, can you try connecting the 5548 using 10 Gig? Or connect the 3750 to the FEX as a workaround(Note that this is not recommended since FEX ports do not run spanning-tree and you will need to enable BPDU filter on the interfaces in question)

It is documented on CCO at
http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9670/qa_c67-618605_ps9670_Products_Q_and_A_Item.html
"
Q. Does the Cisco Nexus 5548P support 1 Gigabit Ethernet ports?
A. All Ethernet ports on the Cisco Nexus 5548P, including the Ethernet ports on expansion
modules, are hardware capable of supporting both 1 and 10 Gigabit Ethernet speeds.
Software support for 1 Gigabit Ethernet will be available in a future software release.

"

[mahbvh]

Hello,

I just ran into the exact same problem with a connexion between a 5548P and 3750 (not 10G). In my setup I don't see any other option than to connect the 3750 to the FEX (2232PP), which bring a few question :

1. Is it safe to use vPC for this connection from to 2 2232PP connected to 2 5548P (vPC peers)
2. Apart from activating BPDU filtering on those ports, what should be done on the STP level
3. In fact I have 2 interconnected 3750s (HSRP, not stacked) at the core fo L3 routing, should I use 1 or 2 vPC from the Nexuses
4. Do you have any idea when the Gigabit interfaces will be supported in the 5548P NX-OS ?

Any insight would be greatly appeciated !

Regards,

Vincent.

[Prashanth Krishnappa]

1) Using redundant links and channel to 3750 will increase the chances o f a bridging loop.. So I would avoid it

2) You need to make sure there are no physical loops.

3  I would not do a dual connection from FEX to a switch

4) In the 5.0(3) release expected around April 2011 timeframe(tentative)

[mahbvh]

Thank you for you help !

I tried today and confirm that a loop is not advisable (at least per VLAN) ! I even managed to make the 5548P crash and reload by itself because of an STP loop (kernel fault).

However I had no problems in my testing with multiple physical links to an upstream 3750 using port channel from the FEX.

Thanks again. I now just hope Cisco won't postpone the next release as we'll be in production by then...

Cheers,

Vincent.

[Ari Darmariyadi]

HI,

The links was successfully built when we changed to 10GB connection.

Cisco TAC reported that the connection from 10G flow to 1G must be using store and forward rather than straight through with current software which caused the connection underruns.

Thank you very much for your information.

Best Regards

Ari

[robert.horrigan]

Can you please let me know best practices for uplinking a single non-failover ACE4710 VPC to 2 FEX connected to individually to two different 5Ks with a VPC?  Will this potentially cause a loop?

[simblecco]

5548 support 1G from NX-OS 5.0(3)N1(1) released at 6 april .

http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps9670/product_bulletin_c25-658155.html

Cisco NX-OS 5.0(3)N1(1) adds support for the following 1 Gigabit Ethernet optics on all SFP+ ports on the base chassis as well as on expansion modules of the Cisco Nexus 5500 platform (including Cisco Nexus 5548P, 5548UP, and 5596UP):

• GLC-T, GLC-SX-MM, and GLC-LH-SM

• SFP-GE-T, SFP-GE-S, and SFP-GE-L

Successfully tested。