:resolve problems

RouterOS Scripting
1

Hi!

I`m having a problem using this script http://wiki.mikrotik.com/wiki/Use_host_names_in_firewall_rules:

running it from cli results:
/system script> run resolvehostnames
failure: dns name does not exist

And the problem is here, at the end of the script from above:
: if ($newip != $oldip) do={:set newip [:resolve $comment]
/ip firewall address-list set $i address=$newip}
}

Tried running this script both on ROS 5.14 and 5.22. The setup is exactly as in the wiki it must be 100% good. Any ideea?

2

Check your IP > Firewall > Address Lists. At least one of the hostnames (Comment) can’t be found by your dns server. For example, I changed the comment of the second entry to a hostname that does not exist. The script ran fine on the first entry. The second entry gave the failure: dns name does not exist error, and the script stopped execution.
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3

THX… I was giving the script an invlaid hostname in the comment was typing mistake.

Ok now the question is how can I skip an invalid hostname so that the script can continue after the error parsing the whole list ?

4

One way is to create a second script that contains the :resolve command, and call the second script from the first using the :execute command. Some examples can be found here: http://forum.mikrotik.com/t/dns-update-stop-exection-script/61541/1

One thing to keep in mind is that the :execute command will not wait for the :resolve of the second script to finish before it continues, so you’ll need to add a delay in the first script.

Also, any variables that will be used between the two scripts (probably $comment and $newip) will need to be global and (I think) declared in both. If I have time, I’ll see about posting an example.

5

Try these 2 scripts. Set the delay below to how long you want to wait before a hostname times out. The name of the first script doesn’t matter, but the name of the second is called from the first, so it must match.

Main script, named whatever:

Delay for X seconds to allow hostname to resolve

:local delay 5

define variables

:global comment
:global newip
:local list
:local oldip

start logging

/log info “[RESOLVE] - START”

Loop through each entry in the address list

:foreach i in=[/ip firewall address-list find] do={

clear newip variable each time

:set newip ""

Get the first five characters of the list name

:set list [:pick [/ip firewall address-list get $i list] 0 5]

If they’re ‘host_’, then we’ve got a match - process it

:if ($list = "host_") do={

Get the comment for this address list item (this is the host name to use)

	:set comment [/ip firewall address-list get $i comment]
	/log info "[RESOLVE] - checking $comment"
	:set oldip [/ip firewall address-list get $i address]
	/log info "[RESOLVE] - old ip: $oldip"
	/log info "[RESOLVE] - calling sub-script"
	:execute script=resolvehostnames-sub

This script does not wait for sub-script to resolve host names, so we need to delay for a time

	:local counter 1
	while ($counter <= $delay) do={
		/log info "[RESOLVE] - waiting for hostname to resolve - attempt $counter"
		:delay 1s

if length of new ip is greater than zero, break out of loop

		:if ([:len $newip] > 0) do={
			:set counter $delay
		}

increment counter

		:set counter ($counter + 1)
	}

if new ip length is greater than zero, an ip was resolved

	:if ([:len $newip] > 0) do={
		/log info "[RESOLVE] - new ip: $newip"

if newip does not equal oldip

		:if ($newip != $oldip) do={
			/log info "[RESOLVE] - ip has changed, updating address list"

Set the address list entry accordingly

			/ip firewall address-list set $i address=$newip
		} else={
			/log info "[RESOLVE] - new ip matches old ip, no change"
		}
	} else={
		/log info "[RESOLVE] - did not get new ip, timed out"
	}
}

}
/log info "[RESOLVE] - END"Sub script, named resolvehostnames-sub# make sure the name of this script matches the one called from the main script (resolvehostnames-sub)
:global comment
:global newip
/log info “[RESOLVE] - trying to resolve $comment from sub-script”
:set newip [:resolve $comment]

6

Hello skot

Thanks a lot for your script, it had been working great, while I was at v5.25, but a few days back I updated to v6.3 and it stopped updating the addresses, it still is running every 3 minutes, but now it does not update them =(

Guys, any ideas what could change between v5.25 and v6.3? or any way to fix it and make it work again?

7

Thanks Skot for this excellent script!

8

The script is working fine for me on v6.3, not sure why it stopped working for you.

First thing I would check is the logs. Look for the [RESOLVE] entries to see if you can find out where the failure is happening. What is the last [RESOLVE] entry that shows up?

For additional testing, you can enclose the entire main script in brackets {}, and then paste it into a terminal window. This may help you to catch any script errors.

9

This is my version of a resolve script it does ip to host name or host name to ip:


wcsnet, copyright © 2010. all rights reserved

script version : 1.0

:do {

:local content
:local newhost
:local oldhost

:log info “******************** starting - ip resolve ip*******************”
:log info “-”

:foreach i in=[/ip firewall address-list find list=“resolve ip” and disabled=no] do={

:set content [/ip firewall address-list get $i address]
:set oldhost [/ip firewall address-list get $i comment]

:do {
:set newhost [:resolve $content]
} on-error={
:log error “dns resolve failure [ ip - resolve ip ]”
}

: if ($newhost != $oldhost) do={
/ip firewall address-list set $i comment=$newhost
:log warning “$[/system identity get name] $comment dns host name changed: $oldhost → $newhost”
}
}

:log info “******************** ending - ip resolve ip********************”

:exec “o - after script run”

} on-error={
:log error “script failure [ ip - resolve ip ]”
}


:do {

:local content
:local newip
:local oldip

:log info “******************** starting - ip resolve host*******************”
:log info “-”

:foreach i in=[/ip firewall address-list find list=“resolve host” and disabled=no] do={

:set content [/ip firewall address-list get $i comment]
:set oldip [/ip firewall address-list get $i address]

:do {
:set newip [:resolve $content]
} on-error={
:log error “dns resolve failure [ ip - resolve host ]”
}

: if ($newip != $oldip) do={
/ip firewall address-list set $i address=$newip
:log warning “$[/system identity get name] $comment ip address changed: $oldip → $newip”
}
}

:log info “******************** ending - ip resolve host********************”

:exec “o - after script run”

} on-error={
:log error “script failure [ ip - resolve host ]”
}

10

Hi,

if you used the first code do a little modification and everything will be ok with new Ver of Fw

:execute script=resolvehostnames-sub
to
:execute script=“resolvehostnames-sub”

the original script will be ok with ver 6.31

I hope could be useful for you,
Maxspeed

from this code:
ros code

Delay for X seconds to allow hostname to resolve

:local delay 5

define variables

:global comment
:global newip
:local list
:local oldip

start logging

/log info “[RESOLVE] - START”

Loop through each entry in the address list

:foreach i in=[/ip firewall address-list find] do={

clear newip variable each time

:set newip “”

Get the first five characters of the list name

:set list [:pick [/ip firewall address-list get $i list] 0 5]

If they’re ‘host_’, then we’ve got a match - process it

:if ($list = “host_”) do={

Get the comment for this address list item (this is the host name to use)

:set comment [/ip firewall address-list get $i comment]
/log info “[RESOLVE] - checking $comment”
:set oldip [/ip firewall address-list get $i address]
/log info “[RESOLVE] - old ip: $oldip”
/log info “[RESOLVE] - calling sub-script”
:execute script=resolvehostnames-sub

This script does not wait for sub-script to resolve host names, so we need to delay for a time

:local counter 1
while ($counter <= $delay) do={
/log info “[RESOLVE] - waiting for hostname to resolve - attempt $counter”
:delay 1s

if length of new ip is greater than zero, break out of loop

:if ([:len $newip] > 0) do={
:set counter $delay
}

increment counter

:set counter ($counter + 1)
}

if new ip length is greater than zero, an ip was resolved

:if ([:len $newip] > 0) do={
/log info “[RESOLVE] - new ip: $newip”

if newip does not equal oldip

:if ($newip != $oldip) do={
/log info “[RESOLVE] - ip has changed, updating address list”

Set the address list entry accordingly

/ip firewall address-list set $i address=$newip
} else={
/log info “[RESOLVE] - new ip matches old ip, no change”
}
} else={
/log info “[RESOLVE] - did not get new ip, timed out”
}
}
}
/log info “[RESOLVE] - END”



Sub script, named resolvehostnames-sub
ros code

make sure the name of this script matches the one called from the main script (resolvehostnames-sub)

:global comment
:global newip
/log info “[RESOLVE] - trying to resolve $comment from sub-script”
:set newip [:resolve $comment]