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...)
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.
The current version is the latest one:
I searched the command reference and cisco search without success.
as for limiting the bandwidth, you could try a CBWFQ configuration such as this (the example is for FTP traffic):
class-map match-all FTP
match protocol ftp
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.:
service-policy output LIMIT_FTP
class-map match-all FTP
match protocol 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
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) ?
thanks for the additional info and comments.
In the bandwidth of version 12.4.5
<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.
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):
type echo protocol ipIcmpEcho 192.168.1.1
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 18.104.22.168 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...
this is interesting :-!
I searched for the rtr command, it seems it has been replaced by ip sla monitor in 12.4 :
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 ...
Here is the translated version, seems to do the job with snmp traps :)
ip sla monitor logging traps
ip sla monitor 2
type echo protocol ipIcmpEcho 10.10.10.1
ip sla monitor reaction-configuration 2 timeout-enable action-type trapOnly
ip sla monitor schedule 2 life forever start-time now
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
What is Wake On Lan ?
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:
I'll have a look to see if it can be translated to TCL.
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...