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Cisco Bug: CSCtf22395 - Poor RTT from TM's filtering servers using IOS Content filtering

Last Modified

Mar 01, 2018

Products (1)

  • Cisco IOS

Known Affected Releases


Description (partial)

 Poor http performance through a router configured with IOS content filtering
 IOS router configured for content filtering that is experiencing poor
performance/and unexpected blocked pages.
 This issue may come and go throughout a day.  You will see evidence of the
poor RTTs (Round Trip Times) in the output of "show policy-map type inspect
zone-pair urlfilter | b Trend"
 Trend URL Filtering is ENABLED
          Trend server : 80)
          Current requests count: 0
          Current packet buffer count(in use): 0
          Maxever request count: 29
          Maxever packet buffer count: 114
          Total cache hit count: 1341
          Total requests sent to URL Filter Server :675
          Total responses received from URL Filter Server :675
          Total error responses received from URL Filter Server :0
          Total requests allowed: 674
          Total requests blocked: 1
          1min/5min Avg Round trip time to URLF Server: 839/839 millisecs
          1min/5min Minimum round trip time to URLF server: 200/200 millisecs
          1min/5min Maximum round trip time to URLF server: 2892/2892 
 A reasonable average 1min/5min round trip time should be somewhere ~250ms
depending on geographic location.
 Furthermore, a regular ICMP ping to these IP addresses, will respond with
times under ~100ms (depending on geographic location), while the application
RTTs (as seen in the output above) will be much higher and inconsistent.
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