You will also need to add you localhost as a source if you want to show that ntp association status on the router apply-flags omit; term allow-ntp { from { source-prefix-list { ntp-server; localhost; } protocol udp; port ntp; } then { policer gen-use-1m; accept; } } show policy-options prefix-list localhost apply-flags omit; apply-path "interfaces lo0 unit 0 family inet address <*>”;
On May 8, 2019, at 7:22 AM, Vincent Bernat <bernat@luffy.cx> wrote:
❦ 8 mai 2019 09:56 +02, Lars Prehn <lprehn@mpi-inf.mpg.de>:
do you NTP sync your AS boundary routers? If so, what are incentives for doing so? Are there incentives, e.g. security considerations, not to do it?
Ensure you have a firewall rule in place to prevent people to use your router for NTP amplification. NTP clients are also servers. On Juniper devices:
policy-options { prefix-list ntp-servers { apply-path "system ntp server <*>"; } } firewall { /* ... */ term accept-ntp { from { source-prefix-list { ntp-servers; } protocol udp; port ntp; } then { policer management-1m; accept; } } }
(see <https://forums.juniper.net/jnet/attachments/jnet/DayOneArchive/77/5/Securing_RouteEngine_v2.pdf> for more details). -- Keep it simple to make it faster. - The Elements of Programming Style (Kernighan & Plauger)