The upgrade guides are here:  https://www.cisco.com/c/en/us/support/switches/nexus-5548up-switch/model.html#InstallandUpgradeGuides   I will note that in the release notes for 7.3.(5)N1(1) and most of the 7.3 train, you'll see the below:   "If you want to upgrade from a release on Cisco NX-OS release 7.1 train or earlier, you must first upgrade to Cisco NX-OS release 7.1(4)N1(1) and then to 7.3(5)N1(1). If you want to upgrade from a release on Cisco NX-OS release 7.2 train or earlier, you must first upgrade to Cisco NX-OS release 7.3(2)N1(1) and then to 7.3(5)N1(1)."   So it looks like it will be a multi step process.   A couple of caveats that I've run into is ensuring some VLANs that you may use don't become reserved by the newer NX-OS.  You can find the reserved VLAN range in the release notes:   https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5500/sw/release/notes/7x/Nexus5500_Release_Notes_7x.html   As for the install, install all should work just fine.  And as for your last question, you can perform the install one at a time.  The vPC will be down until both have the same NX-OS but traffic will flow properly.  Just be sure to follow the install guide if you have FEXs hanging off your 5Ks.   Thanks, Kevin ... View more

You'll want to permit DHCP request to the DHCP server then deny all other 10.x.x.x traffic then permit ip any any. However if your DNS server also resides in the 10.x.x.x, you'll need to permit that as well. The access-list line I added to yours "permit udp any eq bootpc host eq bootps" should be line 1 in the access-list.   Thanks, Kevin   ... View more