Over the last few weeks we have been encountering some strange networking issues at our off site data center.\u00c2\u00a0 The problem was characterized by slow ping times, packet loss, service timeouts, etc.\u00c2\u00a0 After checking all of the network devices on the outside facing link, we turned to the internal infrastructure, our new Cisco 3750 series routers.<\/p>\n
After reviewing the configuration using the ‘show running-config’ command, we checked each of our bonded networking interfaces with ‘the show interface’ command to see if we could uncover any errors, dropped packets, etc.<\/p>\n
Next we decided to check the switches available resources.\u00c2\u00a0 We used ‘show proc cpu’ in order to check the cpu usage.\u00c2\u00a0 This is when we saw the following line:<\/p>\n
‘CPU utilization for five seconds: 97%\/0%; one minute: 97%; five minutes: 98%’<\/p>\n
We immediately knew that this is what we were looking for.\u00c2\u00a0 After contacting Cisco support…we learned that there exists an obscure bug in this version of IOS which causes this kind of behavior.\u00c2\u00a0 If you are interested in learning more about this specific issue, refer to Cisco bug ID<\/span> ‘CSCsd95669’.<\/p>\n The only known fixes at this point are upgrade your version of IOS or restart your switch.\u00c2\u00a0 We have decided to restart the switch and monitor the cpu at regular intervals.\u00c2\u00a0 If this problem were to appear again, at that point we would obviously choose to upgrade.<\/p>\n","protected":false},"excerpt":{"rendered":" Over the last few weeks we have been encountering some strange networking issues at our off site data center.\u00c2\u00a0 The problem was characterized by slow ping times, packet loss, service timeouts, etc.\u00c2\u00a0 After checking all of the network devices on the outside facing link, we turned to the internal infrastructure, our new Cisco 3750 series […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[16],"tags":[],"_links":{"self":[{"href":"https:\/\/www.shainmiley.com\/wordpress\/wp-json\/wp\/v2\/posts\/99"}],"collection":[{"href":"https:\/\/www.shainmiley.com\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.shainmiley.com\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.shainmiley.com\/wordpress\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.shainmiley.com\/wordpress\/wp-json\/wp\/v2\/comments?post=99"}],"version-history":[{"count":4,"href":"https:\/\/www.shainmiley.com\/wordpress\/wp-json\/wp\/v2\/posts\/99\/revisions"}],"predecessor-version":[{"id":103,"href":"https:\/\/www.shainmiley.com\/wordpress\/wp-json\/wp\/v2\/posts\/99\/revisions\/103"}],"wp:attachment":[{"href":"https:\/\/www.shainmiley.com\/wordpress\/wp-json\/wp\/v2\/media?parent=99"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.shainmiley.com\/wordpress\/wp-json\/wp\/v2\/categories?post=99"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.shainmiley.com\/wordpress\/wp-json\/wp\/v2\/tags?post=99"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}