Rearrangement in the Configuration Guides

• The following are the modifications in the CEM guides.

  • Introduction of the Alarm Configuring and Monitoring Guide:

    This guide provides the following information:

    • Alarms supported for SONET and SDH, and their maintenance

    • Alarm profiling feature

    • Auto In-Service States for cards, ports, and transceivers

    For more information, see the Alarm Configuring and Monitoring Guide, Cisco IOS XE 17 (Cisco ASR 920 Series).

  • Rearrangement of Chapter and Topics in the Alarm Configuring and Monitoring Guide:

    • The Auto In-Service States Guide is now a chapter inside the Alarms Configuring and Monitoring Guide.

    • Alarms at SONET Layers topic in the following CEM guides, is added to the Alarms Configuring and Monitoring Guide:

      • 1-Port OC-48/STM-16 or 4 port OC-12/OC-3 / STM-1/STM-4 + 12 port T1/E1 + 4 port T3/E3 CEM Interface Module Configuration Guide

    • The Alarm History and Alarm Profiling chapters are removed from the below CEM Technology guides, and added into the Alarm Configuring and Monitoring Guide:

      • 1-Port OC-48/STM-16 or 4 port OC-12/OC-3 / STM-1/STM-4 + 12 port T1/E1 + 4 port T3/E3 CEM Interface Module Configuration Guide

• Configuring IEEE 802.3ad Link Bundling is now available in Etherchannel Configuration Guide, Cisco IOS XE 17 (Cisco ASR 920 Series).

The Cisco ASR 920 Series Aggregation Services Routers provide a comprehensive and scalable set of Layer 2 and Layer 3 VPN services in a compact package. They are temperature-hardened, small form factor, with high throughput and low power consumption ideal for mobile backhaul, business services and residential voice, video, and data ("triple-play") applications.

Note

The error message "PLATFORM-1-NOSPACE: SD bootflash : no space alarm assert" may occur in the following scenarios: Any sector of SD Card gets corrupted Improper shut down of router power outage. This issue is observed on platforms which use EXT2 file systems. We recommend performing a reload of the router. As a result, above alarm will not be seen during the next reload due to FSCK(file systems check) execution. However, If the error persists after a router reload, we recommend to format the bootflash or FSCK manually from IOS.

• The default command-name command is used to default the parameters under that interface. However, when speed is configured on the interface, the following error is displayed:

  Speed is configured. Remove speed configuration before enabling auto-negotiation

• Adding or deleting the Trunk Ethernet flow points (TEFPs) with scaled bridge-domain, without delay causes the Cisco ASR 920 Series router to crash.

• Virtual services should be deactivated and uninstalled before performing replace operations.

• The Cisco ASR920 Series Routers no longer support the controller and nid-controller commands for the Cisco ME1200 switch.

• The following interface modules (IMs) do not require the activation command for IM boot up, provided no other IM is activated in subslot 0/1 before.

  However, if an IM was activated in the system earlier, deactivate the previously-activated IM before inserting a new IM in system.

  • 16-Port T1/E1 Interface Module

  • 32-Port T1/E1 Interface Module

  • 8-Port T1/E1 Interface Module

  • 4-port OC3/STM-1 (OC-3) or 1-port OC12/STM-4 (OC-12) Interface Module

  • 14-Port Serial Interface Module

  • 6-Port E and M Interface Module

  • 4-Port C37.94 Interface Module

• RS422 works on ports from 0 to 7 only.

• The following restriction is applicable only to:

  • Cisco ASR-920-24SZ-IM, Cisco ASR-920-24SZ-M, and Cisco ASR-920-24TZ-M

  • Cisco ASR-920-20SZ-M

    • Traffic is dropped when packets of size 64 to 100 bytes are sent on 1G and 10G ports.

      • For 64-byte packets, traffic drop is seen at 70% and beyond of the line rate.

      • For 90-byte packets, traffic drop is seen at 90% and beyond of the line rate.

      • For 95-byte packets, traffic drop is seen at 95% and beyond of the line rate.

    • Traffic is dropped when:

      • Traffic is sent on a VRF interface.

      • Traffic is sent across layer 2 and layer 3.

  However, traffic is not dropped when the packet size is greater than 100 bytes, even if the packets are sent bidirectionally at the line rate.

• MPLS VC label packet with time-to-live (TTL) value of 2 is dropped at egress MPLS PE device due to ASIC limitations. During PHP process, MPLS TTL value for the VC label is decremented by one with implicit-null. The VC label-related TTL value is set to 255 while imposing the VC label due to multiple VC switching scenarios.

  Use the no mpls ip propagate-ttl command as the Short Pipe mode for the required label.

• Interface naming is from right to left. For more information, see the Cisco ASR 920 SoftwareConfiguration Guide .

• Packet size greater than 1460 is not supported over IPsec Tunnel.

• Minimal traffic drop might be seen for a moment when higher rate traffic is sent through the IPsectunnels for the first time.

• Before installing the Cisco IOS XE Amsterdam 17.3.1, you must upgrade the ROMMON to version 15_6_43r_s or higher to avoid bootup failure. This is applicable to Cisco ASR-920-12SZ-IM, Cisco ASR-920U-12SZ-IM, and Cisco ASR-920U-12SZ-IM-CC. For Cisco ASR-920-12SZ-A and Cisco ASR-920-12SZ-D, Cisco IOS XE Amsterdam 17.3.1 has to be installed in sub packages mode. Booting in sub package mode takes care of auto upgrade to ROMMON version 15_6_43r_s on bootup. This workaround is not applicable to devices installed with ROMMON version 15.6(9r)S.

• One Ternary Content-Addressable Memory (TCAM) entry is utilized for Segment Routing Performance Measurement. This is required for the hardware timestamping to function.

• While performing an auto upgrade of ROMMON, only primary partition is upgraded. Use the upgrade rom-mon filename command to upgrade the secondary partition of the ROMMON. However, the router can be reloaded during the next planned reload to complete the secondary ROMMON upgrade.

• For Cisco IOS XE Amsterdam 17.3.x , a minimum diskspace of 2 MB is required in the boot flash memory file system for a successful ROMMON auto upgrade process. For a diskspace lesser than 2 MB, ROMMON auto upgrade fails and the router reboots.

• Some router models are not fully compliant with all IETF guidelines as exemplified by running the pyang tool with the lintflag. The errors and warnings exhibited by running the pyang tool with the lint flag are currently non-critical as they do not impact the semantic of the models or prevent the models from being used as part of the toolchains. A script is provided, check-models.sh , which runs pyang with lint validation enabled, but ignoring certain errors. This allows the developer to determine what issues may be present.

  As part of the model validation for this Cisco IOS XE Amsterdam 17.3.1 release, "LEAFREF_IDENTIFIER_NOT_FOUND" and "STRICT_XPATH_FUNCTIONS" error types are ignored.

• Starting with Cisco IOS XE Bengaluru Release 17.5.1, secondary ROMMON partition is also auto upgraded after a successful primary ROMMON partition upgrade is complete. You can reload the router at the next planned reload to complete the secondary ROMMON upgrade.

• For Cisco IOS XE Amsterdam Release 17.3.x, Cisco IOS XE Bengaluru Release 17.4.x, and earlier, the secondary ROMMON partition is not auto upgraded. You must manually upgrade it using the upgrade rom-mon filename command.

• Starting with ROMMON release version 15.6(43r)S, ROMMON version is secure. Once the ROMMON version is upgraded, it cannot be downgraded to a non-secure ROMMON version.

• Secure ROMMON is supported from Cisco IOS XE Amsterdam Release 17.3.1 onwards. However, it is compatible with all the releases.

  Any future secure ROMMON upgrade or downgrade is only possible from Cisco IOS XE Amsterdam Release 17.3.1 onwards.

• Starting with Cisco IOS XE Bengaluru Release 17.4.1, Cisco ASR-920-24SZ-IM, Cisco ASR-920-24SZ-M, Cisco ASR-920-24TZ-M, Cisco ASR 920-10SZ-PD, Cisco ASR-920-12CZ-A/ASR-920-12CZ-D, Cisco ASR-920-4SZ-A/ASR-920-4SZ-D, and Cisco ASR-920-20SZ-M routers are auto upgraded to ROMMON version 15_6_44r_s.

• Any non-secure FPGA bundled releases moving to Cisco IOS XE Bengaluru Release 17.3.x or future releases can result in an FPGA upgrade and a ROMMON upgrade. If FPGA upgrade happens parallely with the ROMMON upgrade, you can only expect a single reload. If FPGA upgrade gets delayed and happens post ROMMON upgrade, two reloads are expected to complete both the upgrade processes. This is followed by a successful bootup of the target release image.

  However, starting with Cisco IOS XE Bengaluru Release 17.5.1, Cisco ASR-920-12SZ-IM, Cisco ASR-920U-12SZ-IM, Cisco ASR-920U-12SZ-IM-CC, Cisco ASR-920-12SZ-A and Cisco ASR-920-12SZ-D, ROMMON and FPGA upgrade are synchronized to happen in a single reload.