Headline
CVE-2023-44181: Enabling and Disabling Storm Control (ELS) | Junos OS
An Improperly Implemented Security Check for Standard vulnerability in storm control of Juniper Networks Junos OS QFX5k devices allows packets to be punted to ARP queue causing a l2 loop resulting in a DDOS violations and DDOS syslog.
This issue is triggered when Storm control is enabled and ICMPv6 packets are present on device.
This issue affects Juniper Networks:
Junos OS
- All versions prior to 20.2R3-S6 on QFX5k;
- 20.3 versions prior to 20.3R3-S5 on QFX5k;
- 20.4 versions prior to 20.4R3-S5 on QFX5k;
- 21.1 versions prior to 21.1R3-S4 on QFX5k;
- 21.2 versions prior to 21.2R3-S3 on QFX5k;
- 21.3 versions prior to 21.3R3-S2 on QFX5k;
- 21.4 versions prior to 21.4R3 on QFX5k;
- 22.1 versions prior to 22.1R3 on QFX5k;
- 22.2 versions prior to 22.2R2 on QFX5k.
Note:
This task uses Junos OS with support for the Enhanced Layer 2 Software (ELS) configuration style. If your switching device is an EX Series switch and runs software that does not support ELS, see Understanding Storm Control. If your switching device is an EX Series switch and runs software that does support ELS, see Using the Enhanced Layer 2 Software CLI.
On EX4300 switches, the factory default configuration enables storm control on all Layer 2 switch interfaces. The default storm control level is set to 80 percent of the available bandwidth used by the combined broadcast, multicast, and unknown unicast traffic streams.
Storm control is not enabled by default on EX9200 switches or MX Series routers.
You can customize the storm control level for a specific interface. You specify the storm control level as the traffic rate in kilobits per second (Kbps) of the combined traffic streams or as the percentage of available bandwidth used by the combined traffic streams.
You can selectively disable storm control for broadcast, multicast, or unknown unicast traffic on all interfaces or on a specified interface. You can additionally disable storm control on registered or unregistered multicast traffic.
In the tasks described in this topic, you use the [edit interfaces interface-name unit 0 family ethernet-switching] hierarchy level to bind the storm control profile for EX Series switches and the [edit interfaces interface-name unit 0 family bridge] hierarchy level to bind the storm control profile for MX Series routers. Starting in Junos OS release 17.4R1 for MX Series routers, you can also configure storm control on logical systems.
Configuring Storm Control
You can configure storm control for a specific interface. The storm control level can be customized by explicitly configuring either the bandwidth level or the bandwidth percentage.
bandwidth-level—Configures the storm control level as the bandwidth in kilobits per second of the combined traffic streams.
bandwidth-percentage—Configures the storm control level as a percentage of the available bandwidth used by the combined traffic streams.
You can also configure a limit for burst-size. The burst size extends the function of the bandwidth limit to allow for bursts of traffic that exceed the configured bandwidth.
To configure storm control:
Create a storm control profile and set the storm control level as the traffic rate in kilobits per second of the combined traffic streams:
Note:
The name of the storm control profile can contain no more than 127 characters.
Bind the storm control profile to a logical interface:
For EX Series Switches (Enterprise Style Configuration Only):
For MX Series routers:
Enterprise Style Configuration:
Service Provider Style Configuration: Starting in Junos OS release 18.3R1, you can configure storm control in the Service Provider Style configuration on MX Series devices.
Disabling Storm Control on Broadcast Traffic
To disable storm control on broadcast traffic:
Create a storm control profile with the storm control level set as the traffic rate in kilobits per second of the combined traffic streams, and exclude broadcast traffic:
Bind the storm control profile to a logical interface:
For EX Series switches:
For MX Series routers:
Disabling Storm Control on All Multicast Traffic
To disable storm control on all multicast traffic:
Create a storm control profile with the storm control level set as the traffic rate in kilobits per second of the combined traffic streams, but exclude multicast traffic:
Bind the storm control profile to a logical interface:
For EX Series switches:
For MX Series routers:
Disabling Storm Control on Registered Multicast Traffic
To disable storm control on only registered multicast traffic:
Create a storm control profile with the storm control level set as the traffic rate in kilobits per second of the combined traffic streams, but exclude registered multicast traffic:
Bind the storm control profile to a logical interface:
For EX Series switches:
For MX Series routers:
Disabling Storm Control on Unregistered Multicast Traffic
To disable storm control on only unregistered multicast traffic:
Create a storm control profile with the storm control level set as the traffic rate in kilobits per second of the combined traffic streams, but exclude unregistered multicast traffic:
Bind the storm control profile to a logical interface:
For EX Series switches:
For MX Series routers:
Disabling Storm Control on Unknown Unicast Traffic
To disable storm control on only unknown unicast traffic:
Create a storm control profile with the storm control level set as the traffic rate in kilobits per second of the combined traffic streams, but exclude unregistered multicast traffic:
Bind the storm control profile to a logical interface:
For EX Series switches:
For MX Series routers:
Disabling Storm Control on Multiple Types of Traffic
To disable storm control on multiple types of traffic; for example, broadcast and multicast traffic:
Create a storm control profile with the storm control level set as the traffic rate in kilobits per second of the combined traffic streams but exclude broadcast and multicast traffic:
Bind the storm control profile to a logical interface:
For EX Series switches:
For MX Series routers:
Release History Table
18.3R1
Starting in Junos OS release 18.3R1, you can configure storm control in the Service Provider Style configuration on MX Series devices.
17.4R1
Starting in Junos OS release 17.4R1 for MX Series routers, you can also configure storm control on logical systems.