{"id":3560,"date":"2012-02-09T22:24:45","date_gmt":"2012-02-10T04:24:45","guid":{"rendered":"http:\/\/gregsowell.com\/?p=3560"},"modified":"2012-02-09T22:27:57","modified_gmt":"2012-02-10T04:27:57","slug":"cisco-absence-of-a-wildcard-mask-in-an-acl","status":"publish","type":"post","link":"https:\/\/gregsowell.com\/?p=3560","title":{"rendered":"Cisco &#8211; Absence Of A Wildcard Mask In An ACL"},"content":{"rendered":"<p>If I have a standard ACL entry like this:<\/p>\n<pre class=\"gs-code\"><code class=\"language-plaintext\">access-list 98 deny 10.0.0.0\r\naccess-list 98 permit any<\/code><\/pre>\n<p>and I apply it to an interface.  What addressing does this block?  <\/p>\n<p>One might think that leaving off the wildcard mask would use the classful boundary(\/8 or 0.255.255.255) of the addressing&#8230;but one would be wrong.  In IOS if you leave off the wildcard mask a wildcard mask of 0.0.0.0 is assumed.  This means the address is considered a host address(a single IP address).  This means the first line equates to :<\/p>\n<pre class=\"gs-code\"><code class=\"language-plaintext\">access-list 98 deny 10.0.0.0 0.0.0.0<\/code><\/pre>\n<p>or<\/p>\n<pre class=\"gs-code\"><code class=\"language-plaintext\">access-list 98 deny host 10.0.0.0<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>If I have a standard ACL entry like this: access-list 98 deny 10.0.0.0 access-list 98 permit any and I apply it to an interface.\u2026<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16,8],"tags":[],"class_list":["post-3560","post","type-post","status-publish","format-standard","hentry","category-cisco","category-networking"],"_links":{"self":[{"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/posts\/3560","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/gregsowell.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3560"}],"version-history":[{"count":2,"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/posts\/3560\/revisions"}],"predecessor-version":[{"id":3562,"href":"https:\/\/gregsowell.com\/index.php?rest_route=\/wp\/v2\/posts\/3560\/revisions\/3562"}],"wp:attachment":[{"href":"https:\/\/gregsowell.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3560"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gregsowell.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3560"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gregsowell.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3560"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}