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<p class=MsoNormal>Are firewall vendors working to increase the default
settings for DNS maximum packet size in order to better support EDNS and DNSSEC?<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Cisco firewalls have a default maximum packet size for DNS set
to 512 bytes, and I’m going to guess similar settings exist for other
vendor firewalls.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>A recent inquiry to increase the default setting for DNS maximum
packet size enforcement on Cisco firewalls was answered with “the default
configuration change is not on our firewall roadmap”.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Is anybody working to get the vendors to put this change into
product roadmaps, especially as year-end approaches and the OMB deadline is
reached?<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Example configuration change for Cisco ASA and FWSM shown
below:<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>--/--<o:p></o:p></p>
<p class=MsoNormal>conf t<o:p></o:p></p>
<p class=MsoPlainText>policy-map type inspect dns preset_dns_map<o:p></o:p></p>
<p class=MsoPlainText> parameters<o:p></o:p></p>
<p class=MsoPlainText> message-length maximum <b>4096</b><o:p></o:p></p>
<p class=MsoPlainText>policy-map global_policy<o:p></o:p></p>
<p class=MsoPlainText> class inspection_default<o:p></o:p></p>
<p class=MsoPlainText> inspect dns preset_dns_map<o:p></o:p></p>
<p class=MsoNormal>end<o:p></o:p></p>
<p class=MsoNormal>--/--<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
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