Hi,
When connecting to my ISP I receive a /56 IPv6 prefix for PD. Updates for RAs are sent to two irbs. Each irbreceives a /64 which hosts use for their purpose.
Issue is that the DHCPv6 client under pp0.0 family inet6 does not respect the client lease time and defaults it to 1day.
My ISP sets the 2^32-1 value of 4,294,967,295. for both preferred and valid lifetime.
This value is set in accordance with RFC 3633 Section 10 by the DHCP server.
preferred-lifetime: The recommended preferred lifetime for the IPv6
prefix in the option, expressed in units of
seconds. A value of 0xFFFFFFFF represents
infinity.
valid-lifetime: The valid lifetime for the IPv6 prefix in the
option, expressed in units of seconds. A value of
0xFFFFFFFF represents infinity.
This value is set by the Advertise message, Request message, Reply message. (Attached JDHCPD debug file)
Essentially the most important piece of information from that file are after the Reply message. where the server acknowledges the duration I see that it in the function
dhcpv6_client_process_ack_packet
sets leasetime=-1. This to me seems undefined or unexpected value. Or overflow ?
It then proceeds to put a lease time of 43200. However the lease under show dhcpv6 client binding detail it shows the lease to be valid for twice this amount at 86400.
Oct 15 16:55:43.386561 [MSTR][DEBUG][default:default][N/A][INET6][pp0.0][SID=0] dhcpv6_client_process_ack_packet: IAPD Prefix is 2a02:2f0a:4503:9700:: with Prefix len 56 leasetime=-1 Oct 15 16:55:43.386629 [MSTR][DEBUG] jdhcpd_rc_lease_timer_start: starting lease timer for 43200 seconds
After 43200 seconds it will begin to issue Renews to the DHCP server. However both the server and client concluded that they use 4,294,967,295. seconds so most likely by ISP policy renews are not allowed.
In any case this is pretty annoying. I know Juniper's DHCP implementation is flaky. Also my ONU handles it as expected setting the proper lease time.
Each prefix has valid and preferred lifetimes whose durations are
specified in the IA_PD Prefix option for that prefix. The requesting
router uses Renew and Rebind messages to request the extension of the
lifetimes of a delegated prefix.
This is true as it sets the lease time to 86400 but if it kept the lease as the DHCPv6 server gave it then no renew would occur.
- Seen on SRX210he2 - JUNOS Software Release [12.3X48-D65.1]
- also on SRX320 15.1X49-D75/ 15.1X49-D130
I'm sure workardounds exists but I'm looking to know if there are plans to fix this as it's a very inconvenient issue.