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Sumanta_88744's avatar
Sumanta_88744
Icon for Cirrus rankCirrus
Jun 11, 2016

Universal Persistence with X-forwarder

Hi Experts   Can I use Universal persistence using x-forwarder with i-rule? I would have each x-forwarded IP stick to the same back-end pool member. Will this work? Can you please share code? Any ...
application delivery
cloud
iRules
LTM
  • Yann_Desmarest_'s avatar
    Yann_Desmarest_
    Jul 20, 2016

    A formatted version of the "Per VS" rate limiting. You can apply the same irule to all standard VS using UIE persistence.

     

    when RULE_INIT {
    set static::maxReqs 3;
    set static::timeout 60;
}

when HTTP_REQUEST {
        set vs [URI::basename [virtual]]
        if { [HTTP::header exists "X-Forwarded-For"] } {
            set client_IP_addr [getfield [lindex  [HTTP::header values "X-Forwarded-For"]  0] "," 1]
        } else {
            set client_IP_addr [IP::client_addr]
        }
        if { ([HTTP::method] eq "GET") and ([class match [string tolower [HTTP::uri]] ends_with $vs_URI_LIST_TO_LIMIT] ) } {

            whitelist
            if { [class match [IP::client_addr] equals $vs_ips_whitelist] }{
               return
            }
            set getcount [table lookup -notouch "$vs_$client_IP_addr:[HTTP::uri]"]
            if { $getcount equals "" } {
                table set "$vs_$client_IP_addr:[HTTP::uri]" "1" $static::timeout $static::timeout
            } else {
                if { $getcount < $static::maxReqs } {
                    table incr -notouch "$vs_$client_IP_addr:[HTTP::uri]"
                } else {
                    reject
                }
            }
        }
        persist uie $clientip 
}

when HTTP_RESPONSE { 
    persist add uie $clientip 
}

     

Kai_Wilke's avatar
Kai_Wilke
Icon for MVP rankMVP
Aug 16, 2016

Hi Sumanta,

to [persist uie] your clients by either using an existing X-Forwarded-For header (prefered method) or by using the [IP::client_addr] of the underlying TCP session (fallback method), you may take a look to the rather simple iRule below...

 

when HTTP_REQUEST { 
    if { [set orig_ip [HTTP::header value "X-Forwarded-For"]] eq "" } { 
        set orig_ip [getfield [IP::client_addr] "%" 1]
    } 
     Tweak the persistence table timeout as needed. 1800 is the configured duration in seconds.
    persist uie $orig_ip 1800
}

 

Note: Issue a tmsh show /ltm persistence persist-records mode universal to list the currently active uie persistence records.

Cheers, Kai