nrt ngn prefix change

[sorah]

• https://github.com/kmc-jp/infra/issues/987
• https://github.com/sorah/sorah-infra/issues/7

https://scrapbox.io/rknet/issue214

[sorah]

設定変更ログ https://scrapbox.io/rknet/issue214

rk@br-01-nrt> show bgp summary | match 6500
2001:df0:8500:ca22:8::a       65001         24         24       0       2          23 Establ
2001:df0:8500:ca22:10::b       65003         34         37       0       5        2:52 Establ