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Cisco IOS XE 3S Release Notes for the Cisco ASR 903 Router
OL-26630-08
Chapter
Limitations and Restrictions
Limitations and Restrictions in Cisco IOS XE Release 3.8(0)S
The following limitations apply to the Cisco ASR 903 Router in IOS XE Release 3.8(0)S:
ATM IMA Limitation
•
You can create a maximum of 16 IMA groups on each T1/E1 interface module.
•
High Availability (HA) is not supported with IMA.
Bidirectional Forwarding Detection Limitations
•
The ASR 903 does not support BFD timers with a value of less than 200 ms x 3 (using a multiplier
of 3) for software-based BFD sessions.
Bridge Domain Interface Limitation
•
The
mtu
command is not supported on BDI interfaces; however the
ip mtu
command is supported.
Clocking and Timing Limitation
•
Only a single clocking input source can be configured within each group of eight ports (0-7 and
8-15) on the T1/E1 interface module using the network-clock input-source command.
•
Synchronous Ethernet clock sources are not supported with PTP. Conversely, PTP clock sources are
not supported with synchronous Ethernet. However, you can use hybrid clocking to allow the router
to obtain frequency using Synchronous Ethernet and phase using PTP.
Dying Gasp Limitations
The ASR 903 supports dying gasp under the following scenarios:
•
Ethernet OAM is disabled
•
Interface is shut down
•
Interface enters error-disabled state
•
Router reload
Dying Gasp is not supported in the event of a power failure.
EFP Limitations
•
QinQ is not supported on trunk EFP interfaces.
•
The Cisco ASR 903 Router supports a maximum of 24 trunk EFPs.
Equal Cost Multipath Limitation
•
The Cisco ASR 903 Router supports a maximum of 4 Equal Cost Multipath (ECMP) links.
Ethernet IM Limitations
•
The Cisco ASR 903 Router does not support the Facilities Data Link (FDL) on Ethernet interfaces.
•
The Cisco ASR 903 Router does not support the
mac-address
command on Gigabit Ethernet
interface modules.
•
10 Gigabit Ethernet interface modules are not supported in slots 4 and 5.
•
When you install a Gigabit Ethernet IM in the topmost interface module slot (slot 5), the last
interface (interface GigabitEthernet0/5/0) is not operational; the port is reserved for internal
communication.