Release Notes for Cisco IOS Release 15.6(2)T
Image Information and Supported Platforms
The Cisco 5921 ESR has the following limitation:
Obtaining Documentation and Submitting a Service Request
The following release notes support Cisco IOS Releases 15.6(2)T and higher releases. These releases support the Cisco 5900 Embedded Services Routers (ESR) platforms. These release notes are updated to describe new features, limitations, troubleshooting, recommended configurations, caveats, and how to obtain support and documentation.
Note You must have a Cisco.com account to download the software.
Cisco IOS Release 15.6(2)T includes the following Cisco IOS images:
The following documentation is available:
http://www.cisco.com/c/en/us/td/docs/solutions/GGSG-Engineering/15-4-3M/config-guide/Configuration-Guide.html
http://www.cisco.com/c/dam/en/us/td/docs/solutions/GGSG-Engineering/Cisco_5921/Cisco_5921_ESR_Integration.pdf
http://www.cisco.com/c/en/us/products/ios-nx-os-software/ios-software-releases-listing.html
The following new features are supported with release 15.6(2)T.
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.
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:
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:
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).
Caveats describe unexpected behavior in Cisco IOS releases. Caveats listed as open in a prior release are carried forward to the next release as either open or closed (resolved).
BIA address was not taking the NIC mac address in the 5921 router.
When DLEP and multiple VMIs were used, multicast was not forwarded by the receiving router after re-routing between VMI interfaces.
The 5940 router was crashing while launching the R2CP client session.
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.
The ping command was failing on the 5921 with Q_in_Q
The 5921 router was unable to read the VLAN tags from Linux kernel-2.6.32-504.23.4.el6.i686 and later.
On the 5921 router, the vlan dot1q tag was not working over bridge interface.
On the 5921 router, packet loss was observed on over-subscription of queue in QOS in testing.
The CPU utilization reaches 100% while running DLEP v1.7.
May hit when running the combination of DLEPv1.7, R2CP and PPPOE.
The script (c5921-swr-init.sh) that is delivered in the package with the 5921 tar image does not stop all the processes.
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.
Forcefully kill the process running on the Linux server using the kill - 9 <
process id >
command.
For information on obtaining documentation, using the Cisco Bug Search Tool (BST), submitting a service request, and gathering additional information, see What’s New in Cisco Product Documentation at: http://www.cisco.com/en/US/docs/general/whatsnew/whatsnew.html.
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