Storm Control - Maipu

Today in this section, We will see about Maipu Switching storm control function. Many times, we need to configure this function at the time of deployment for switches, Majorly in service provider network this is must to ensure loop free and broadcast free network.

Storm control -

This command is used to strict the size of the broadcast flow permitted to pass on an Ethernet port. When the broadcast flow on the port exceeds the value configured by the user, the system discards the packets which exceed the limitation of the broadcast flow. In this way the proportion of the broadcast flow can be reduced to the limited range and the normal operation of network services is ensured.

Following types of the restricted packets can be configured:

Broadcast packet，broadcast；

Unknown multicast packet，multicast。

You can configure storm control for pps(packets per second) and bps(bits per second).

Syntax - storm-control {broadcast|multicast|unicast} {pps packets|bps rate-bps}

To configure storm control for bps(bits per second). The unit of bps is kbps and the granularity is 64kbps. The value range is 64-8000000, that is, 64kpbs to 8G.

After the configuration, the status of the storm control can be displayed via show  stormcontrol [portlist].

Default status: The storm control is not configured.

Storm-control action

This command is used to configure the action executed after storm suppression happens, that is, disable the port pr send TRAP alarm. To send TRAP, first enable snmp service and enable the corresponding switch.

The action types:

Disable port: shutdown;

Send TRAP alarm: trap;

 Let’s see this function in action with configuration - 

 Topology

 Test purpose:

We need to make sure, If switchport receive unknown broadcast and multicast. It will shutdown the port.

port 0/1

 port-type uni

 uni-isolate community

 storm-control broadcast pps 500

 storm-control multicast pps 500

 storm-control action shutdown

 ethernet uni-id UNI-port-0/1

 ethernet uni-type bundling

 exit

This configuration , if more than 500 packet per second multicast/broadcast.It will active the action (shutdown the interface)

### You can configure in bps also.

show run and show version information

  

All IOS for MP 3400 will support this feature. (released from 2009)

Captures

Case one(test the unknown broadcast packet)

Here we can see under the every second the software is sending 512 unknown broadcast packets to switchport and in switch, we have defined that : storm-control broadcast pps 500. In this time the switch interface port 0/1 automatically shutdown as we configured the action.

Output -

After that you can just use command no shutdown let this port UP.

Case two(test the unknown multicast packet)

When the port 0/1 receive overload multicast it will automatically shutdown the port and give you the information. This feature is one part of err-disable functions.

Tested on following IOS version:

MP3400: sp1-g-6.1.35(RL08-07).bin and 6.2.19.pck

Hope this report will help you..

For feedback and queries, Plz put comments with your mail id.

DHCP - Configurations

As we discussed about DHCP in last post, Let’s have a look for configurations.

Instance 1

DHCP configuration

Description -

The f0 port of the Maipu router A is connected to two PCs and router B. Router A serves as the DHCP server; the two PCs and router B serve as the client. Here, the IP address of the f0 port on router A is 199.1.1.1.

The configuration procedure is as follows:

Router A configures the DHCP commands in the global mode:

Command	Description
router A#configure terminal
router A(config)#ip dhcp pool  maipu	To define one DHCP address pool
router A(config)# ip dhcp excluded-address  199.1.1.15	199.1.1.15 cannot be distributed.

The commands of router A in the pool of DHCP:

Command	Description
router A# configure terminal
router A(config)#ip dhcp pool maipu	To define one address pool
router A(dhcp-config)#range 199.1.1.11 199.1.1.60 255.255.255.0	To define one IP address segment
router A(dhcp-config)#dns-server 61.139.2.2	To specify the DNS address of the client carried by the DHCP of router A
router A(dhcp-config)#default-router 199.1.1.1	To specify the default gateway of the client carried by the DHCP of router A
router A(dhcp-config)#lease 7 10 30	The lease of the distributed address is seven days, ten hours and 30 minutes.

On the f0 port of router B:

Command	Description
router B# configure terminal
router B(config-if-fastethernet0)#ip address dhcp	To distribute addresses via the DHCP server

Instance 2

DHCP configuration

Description -

In the above figure, router A is dhcp server, and router B is dhcp relay. F0 of router A address is 129.255.1.1, f0 of router B is 199.1.1.1, and the ip address of e0 is 129.255.1.2. Therefore, the address pool of router A is to distribute addresses for pc1 and pc2

The configuration procedure is as follows:

Router A configures the DHCP commands in the global mode:

Command	Description
router A#configure terminal
router A(config)#ip dhcp pool  maipu	To define one DHCP address pool
router A(config)# ip dhcp excluded-address  199.1.1.15	199．1．1．15 cannot be distributed.

The commands of router A in the pool of DHCP:

Command	Description
router A# configure terminal
router A(config)#ip dhcp pool maipu	To define one address pool
router A(dhcp-config)#range 199.1.1.11 199.1.1.60 255.255.255.0	To define one IP address segment
router A(dhcp-config)#dns-server 61.139.2.2	To specify the DNS address of the client carried by the DHCP of router A
router A(dhcp-config)#default-router 199.1.1.1	To specify the default gateway of the client carried by the DHCP of router A
router A(dhcp-config)#lease 7 10 30	The lease of the distributed address is seven days, ten hours and 30 minutes.
router A(dhcp-config)#exit
router A(config)#ip route 0.0.0.0 0.0.0.0 129.255.1.2	The route from the server to the client (it is one default route)

router B configuration:

Command	Description
router B# configure terminal
router B(config)# ip dhcp-server  129.255.1.1	To point to the DHCP server

Monitoring Commands

Command	Description
show ip dhcp binding	To view the list of the hosts that are distributed with IP addresses on the DHCP server
show ip dhcp pool-statistic	To view the statistics information of the current DHCP address pool
show ip dhcp arp-proxy-ipaddr	The command is used by DHCP over IPsec to display address information of the remote customers surrogated by the gateway
show running-config ip dhcp	To view the DHCP configuration information
show ip dhcp lease	To display the lease information distributed to the current DHCP
show ip dhcp ping	To display the parameters when DHCP configures ping detection
show ip dhcp pool	To display the configured DHCP address pool information
show ip dhcp excluded-pool	To display the configured address pool that is not distributed by DHCP

Debugging Commands

Command	Description
clear ip dhcp arp-proxy-ipaddr [address | all]	It is used by DHCP over IPsec to clear up the address information of the remote customers surrogated by the gateway
clear ip dhcp binding	To clear up the DHCP server binding information
(no) debug ip dhcp {packet | lease | events | relay}	To enable/disable the DHCP debugging switch Packet: to display the DHCP switching packets; Lease: to display the information of the DHCP lease; Events: to display the DHCP switching process; Relay: to display the DHCP proxy information;

Hope this information is helpful for you.

For feedbacks and queries, Plz put comment with your mail id.