Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Community Member

WOL (wake on lan) on Cisco 1721 + CAR <8kbps + server monitoring ?

Hi guys,

on one of our remote sites, we've installed a 1721 with ADSL.

We'd like to be able to log onto the router, to be able to wake up a server. This means sending a magic packet from the router IOS itself ...

Is there a way to do this?

We'd also like to limit the bandwith of some applications to 2-3 Kbps... I saw CAR was limited from 8 kbps... any way to do this?

Also would it be possible to have an Snmp trap (oe even email) sent from the router when it sees a server is down (kind of Load balancer keepalives...)

Thx!

10 REPLIES
Silver

Re: WOL (wake on lan) on Cisco 1721 + CAR <8kbps + server monito

I think sending the Magic number from 1721 router to the client also depends on the IOS version in the router.Because, new IOS versions of cisco have many enhanced features.So, let me know what is the IOS version u are using in 1721 MAR.

Community Member

Re: WOL (wake on lan) on Cisco 1721 + CAR <8kbps + server monito

Hello smahbub,

The current version is the latest one:

c1700-sy7-mz.124-5.bin

I searched the command reference and cisco search without success.

Thanks

VIP Purple

Re: WOL (wake on lan) on Cisco 1721 + CAR <8kbps + server monito

Hello,

as for limiting the bandwidth, you could try a CBWFQ configuration such as this (the example is for FTP traffic):

ip cef

!

class-map match-all FTP

match protocol ftp

!

policy-map LIMIT_FTP

class FTP

bandwidth 3000

!

interface FastEthernet0/0

service-policy input LIMIT_FTP

The actual values configurable under the class depend on your IOS version. You could also try 'bandwidth percent', that value depends on the 'bandwidth' configured under the interface, e.g.:

ip cef

!

interface ATM0/0

bandwidth 2048

service-policy output LIMIT_FTP

!

class-map match-all FTP

match protocol ftp

!

policy-map LIMIT_FTP

class FTP

bandwidth percent 1

In this example, the available bandwidth for FTP traffic is limited to 1% of 2048.

As for sending 'wakeup' packets to the servers, I am not sure that this can be done from a Cisco device. Your IOS version supports the command scheduler, which might let you send the necessary traffic to the server. Have a look at the document below:

Cisco IOS Software Releases 12.3 Mainline

Command Scheduler

http://www.cisco.com/en/US/products/sw/iosswrel/ps5187/products_feature_guide09186a00801b0695.html

With regard to traps and emails in the event of the server interface going up or down, by default, an SNMP trap is sent when the link status changes. Sending an email would be a function of the management system...which one are you using (e.g. HP OpenView) ?

Regards,

GP

Community Member

Re: WOL (wake on lan) on Cisco 1721 + CAR <8kbps + server monito

Hello GP,

thanks for the additional info and comments.

In the bandwidth of version 12.4.5

router(config-pmap-c)#bandwidth ?

<8-2000000> Kilo Bits per second

percent % of total Bandwidth

remaining % of the remaining bandwidth

I could only see 8 Kbits, which makes me thinks I can not go lower, but indeed, I can try putting the percent and a bandwith parameter on the ATM interface. (I could put 400Kbits bandwith and 1

% to have 4 Kb e.g.)

Can you send an snmptrap when an IP is down (not an interface), seen from the router, not from the switch ?

I will check the Command scheduler, thanks.

Christophe

VIP Purple

Re: WOL (wake on lan) on Cisco 1721 + CAR <8kbps + server monito

Hello Christophe,

you could try and configure the following on your router (the IP address to be monitored is 192.168.1.1 in this example, and the SNMP trap is sent to 172.16.1.1, these addresses are likely different in your situation):

rtr 1

type echo protocol ipIcmpEcho 192.168.1.1

threshold 2

timeout 1000

frequency 3

rtr schedule 1 life forever start-time now

rtr reaction-configuration 1 connection-loss-enable timeout-enable action-type trapOnly

!

snmp-server enable traps rtr

snmp-server host 2.2.2.2 version rtr

Whenever the IP address is not reachable, an SNMP trap is sent to the SNMP host....

Let me know if you have trouble configuring this...

Saluts,

GP

Community Member

Re: WOL (wake on lan) on Cisco 1721 + CAR <8kbps + server monito

Hello GP,

this is interesting :-!

I searched for the rtr command, it seems it has been replaced by ip sla monitor in 12.4 :

http://www.cisco.com/en/US/products/sw/iosswrel/ps5207/products_feature_guide09186a008044d161.html

Looking around for the new features, I found an interesting article : http://www.enterprisenetworksandservers.com/monthly/art.php/1684

where they talk about Embedded Syslog Manager (ESM) which could send an email.

I will have a look at both.

At the moment I could not link the command scheduler with a way to generate a magick packet ...

Merci!

Christophe

Community Member

Re: WOL (wake on lan) on Cisco 1721 + CAR <8kbps + server monito

Here is the translated version, seems to do the job with snmp traps :)

thx!

ip sla monitor logging traps

ip sla monitor 2

type echo protocol ipIcmpEcho 10.10.10.1

timeout 1000

frequency 3

ip sla monitor reaction-configuration 2 timeout-enable action-type trapOnly

ip sla monitor schedule 2 life forever start-time now

VIP Purple

Re: WOL (wake on lan) on Cisco 1721 + CAR <8kbps + server monito

Hello Cristophe,

thanks for the info, I didn't know that 'rtr' has been replaced by 'ip sla'...

As for the Magic Packet, I have been trying to find out exactly what the structure is of that packet. According to the article linked below, it uses subnet-directed broadcasts. The problem is that ip directed broadcasts are disabled by default since IOS 12.0, since they can be used for e.g. smurf attacks.

I doubt that the router itself can generate those WOL packets, but you might want to have a look at this article from Scott Morris, which deals with the problem. Scott suggests to apply an access list and allow UDP subnet-level broadcasts...

Wake Up and Smell the Magic Packets

http://tcpmag.com/qanda/article.asp?EditorialsID=320

What is Wake On Lan ?

http://www.depicus.com/wake-on-lan/what-is-wake-on-lan.aspx

Saluts,

GP

Community Member

Re: WOL (wake on lan) on Cisco 1721 + CAR <8kbps + server monito

Hello GP,

thinking of it, in 12.4 there is this TCL scripting thing. Which may allow me to generated a "crafted" packet ...

I found a C code to generate the magic packet:

http://www.codeproject.com/useritems/WOL.asp?df=100&forumid=211282&exp=0&select=1256160#xx1256160xx

I'll have a look to see if it can be translated to TCL.

br,

Christophe

Community Member

Re: WOL (wake on lan) on Cisco 1721 + CAR <8kbps + server monito

Hello GP,

I configured the CBWFQ like described, but it seems it does not limit the traffic, like hoped.

Reading some docs on it, can it be that in fact it will reserve the bandwith for this application, in case the BW is used by other application.

This would mean I could use 100% BW for other application, but when FTP is started, FTP would receive the reserverd percent...

Any idea?

Thx!

473
Views
0
Helpful
10
Replies
CreatePlease to create content