Release Notes for Cisco IOS Release 15.6(2)T on the 5900 Series ESR Platforms

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Add 200Mbps to the 5921

There are new licenses that support additional throughput speeds on the 5921. The c5921 universalk9 and entbasek9 images now support the 200Mbps PIDs shown in the following table.

The Cisco 5921 ESR has the following limitation:

With the 5921 ESR, several situations have been encountered in which the e1000e Ethernet driver strips VLAN tags before a frame reaches the 5921. This will result in dot1q trunking not performing properly (the 5921 will receive frames with no VLAN tag, even though it is configured to expect VLAN tags). In IOS, you will notice this by seeing ARP or ping failures.
If you see such behavior, please issue the following debug command from IOS:

# debug arp

Now, try the ping again. If the VLAN tag stripping issue is present, you will see a "wrong cable" message similar to the following:

Now switch to the Linux command line and see if the e1000e driver is being used by issuing the following command (using eth0 as an example):

 

From the Linux command line, verify the VLAN mode of the device:

If the VLAN mode is enabled, this indicates that the driver is stripping the VLAN tags.

To remedy this using CentOS, please upgrade to the latest e1000e driver by following these steps from the Linux command line:

If the process ends with the following message, ignore it:

From the Linux command line, verify that the new driver has been activated:

Linux kernel patch which causes 802.1q tag removal is committed into the following streams:

6.5.z: 2.6.32-431.61.2

6.6.z: 2.6.32-504.23.4.el6

6.7: 2.6.32-511.el6

Any Linux kernel within each of these streams that is at the above versions or later would have the 802.1q removal change. incorporated.

Add the below entry in the SWROPTIONS file when the Linux Kernel/driver strips dot1q tag before the packet reaches the 5921 (if running IOS version is 15.6(2)T).

linux-vlan-stripped-from-pak=TRUE

Cisco IOS Release 15.6(2)T

The following sections list caveats for Cisco IOS Release 15.6(2)T:

Closed Caveats

• CSCuy31565

BIA address was not taking the NIC mac address in the 5921 router.

• CSCuy09274

When DLEP and multiple VMIs were used, multicast was not forwarded by the receiving router after re-routing between VMI interfaces.

• CSCuy30908

The 5940 router was crashing while launching the R2CP client session.

• CSCuy33157

There existed a condition on the 5921 router where an access point was moved to a disabled state, and then a reload command was issued, causing a crash with the router.

• CSCuy11462

The ping command was failing on the 5921 with Q_in_Q

• CSCuw55129

The 5921 router was unable to read the VLAN tags from Linux kernel-2.6.32-504.23.4.el6.i686 and later.

• CSCuy01278

On the 5921 router, the vlan dot1q tag was not working over bridge interface.

• CSCuw64684

On the 5921 router, packet loss was observed on over-subscription of queue in QOS in testing.

Open Caveats

• CSCuv99496

The CPU utilization reaches 100% while running DLEP v1.7.

Symptom :

May hit when running the combination of DLEPv1.7, R2CP and PPPOE.

There is no workaround.

• CSCuy87412

The script (c5921-swr-init.sh) that is delivered in the package with the 5921 tar image does not stop all the processes.

Symptom:

The c5921 process running on linux will not stop all the process related to the application when the script c5921-swr-init.sh stop is executed.

Workaround:

Forcefully kill the process running on the Linux server using the kill - 9 < process id > command.

 

Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.

 

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