{"id":624,"date":"2010-04-30T13:57:04","date_gmt":"2010-04-30T12:57:04","guid":{"rendered":"http:\/\/lendl.priv.at\/blog\/?p=220"},"modified":"2026-01-26T12:14:11","modified_gmt":"2026-01-26T11:14:11","slug":"dear-cisco","status":"publish","type":"post","link":"https:\/\/lendl.priv.at\/blog\/2010\/04\/30\/dear-cisco\/","title":{"rendered":"Dear Cisco"},"content":{"rendered":"<p>I&#8217;m doing a bit of network monitoring with SNMP again, and stumbled upon yet another cisco SNMP bug. Back when I wrote the pan-european NMS for KPNQwest, I had to work-around a good number of bugs in the IOS snmp agent, but this time it&#8217;s a bug in the MIB file:<\/p>\n<p>Using the  CISCO-BGP4-MIB, I can graph the state of my BGP peerings. All fine, when looking at<\/p>\n<pre><code>\n    CbgpPeerAddrFamilyPrefixEntry ::= SEQUENCE {\n        cbgpPeerAcceptedPrefixes        Counter32,\n        cbgpPeerDeniedPrefixes          Gauge32,\n        cbgpPeerPrefixAdminLimit        Unsigned32,\n        cbgpPeerPrefixThreshold         Unsigned32,\n        cbgpPeerPrefixClearThreshold    Unsigned32,\n        cbgpPeerAdvertisedPrefixes      Gauge32,\n        cbgpPeerSuppressedPrefixes      Gauge32,\n        cbgpPeerWithdrawnPrefixes       Gauge32\n        }\n<\/code><\/pre>\n<p>you notice that the Gauge32 vs. Counter32 types are mixed up.<\/p>\n<p>cbgpPeerAcceptedPrefixes is the only Gauge here, whereas cbgpPeerDeniedPrefixes, cbgpPeerAdvertisedPrefixes, cbgpPeerSuppressedPrefixes and cbgpPeerWithdrawnPrefixes are actually Counters, e.g.<\/p>\n<pre><code>\n    cbgpPeerWithdrawnPrefixes  OBJECT-TYPE\n        SYNTAX      Gauge32\n        MAX-ACCESS  read-only\n        STATUS      current\n        DESCRIPTION\n                \"This counter is incremented when a route prefix,\n                 which belongs to an address family, is withdrawn on\n                 this connection. It is initialized to zero when the\n                 connection is undergone a hard reset.\"\n        ::= { cbgpPeerAddrFamilyPrefixEntry 8 }\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>I&#8217;m doing a bit of network monitoring with SNMP again, and stumbled upon yet another cisco SNMP bug. Back when I wrote the pan-european NMS for KPNQwest, I had to work-around a good number of bugs in the IOS snmp agent, but this time it&#8217;s a bug in the MIB file: Using the CISCO-BGP4-MIB, I [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11],"tags":[],"class_list":["post-624","post","type-post","status-publish","format-standard","hentry","category-system-administration"],"_links":{"self":[{"href":"https:\/\/lendl.priv.at\/blog\/wp-json\/wp\/v2\/posts\/624","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lendl.priv.at\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lendl.priv.at\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lendl.priv.at\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lendl.priv.at\/blog\/wp-json\/wp\/v2\/comments?post=624"}],"version-history":[{"count":1,"href":"https:\/\/lendl.priv.at\/blog\/wp-json\/wp\/v2\/posts\/624\/revisions"}],"predecessor-version":[{"id":929,"href":"https:\/\/lendl.priv.at\/blog\/wp-json\/wp\/v2\/posts\/624\/revisions\/929"}],"wp:attachment":[{"href":"https:\/\/lendl.priv.at\/blog\/wp-json\/wp\/v2\/media?parent=624"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lendl.priv.at\/blog\/wp-json\/wp\/v2\/categories?post=624"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lendl.priv.at\/blog\/wp-json\/wp\/v2\/tags?post=624"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}