思科说可将loopback接口地址配置到SRv6 locator网段下，那么，反过来可以吗？

思科下面网站提到如下描述：可以将loopback接口地址（BBBB:BB00:0001::1/128）配置到SRv6 locator网段下（比如BBBB:BB00:0001::/48），这样，IGP仅发布SRv6 locator网段，不需要再发布loopback地址。

那么，反过来可以吗？即配置loopback接口地址为（BBBB:BB00:0001::1/48），配置IGP发布loopback网段，配置SRv6 locator到loopback网段下（比如BBBB:BB00:0001::/48），这样，就不需要再配置IGP发布SRv6 locator其它节点根据loopback的网段也可以寻址到SRv6 locator。

Configure Design and Migration Best Practices for Segment Routing over IPv6 - Cisco

Loopback Address Planning

In the SRv6 deployment, the loopback address can be allocated from the locator prefix range or independently from the planned infrastructure IPv6 range as well. However, if the loopback address is allocated from the locator prefix range then it is reachable via the locator prefix range announcement itself and does not have to be separately advertised as a /128 prefix between the domains.

For example, if the uSID locator block is BBBB:BB00:0001/48 then the loopback address can be BBBB:BB00:0001::L /128 with L=1-F. IGP ISIS takes care to advertise the locator block so there is no need to advertise the loopback block separately.

Note: Dynamic SIDs do not conflict with SIDs/prefixes that exist, like loopback addresses from the locator block.

Advantages of Loopback Addressing from Locator Block

There are several advantages to allocate loopback addressing from the locator block:

• No additional IGP prefixes help in improved scale
• No additional FIB entries help in improved Hardware scale

• BGP NH and SID share fate