Hi Xiaohu, Please see inlined.
On Wed, 2014-03-19 at 01:27 +0000, Xuxiaohu wrote: > > > > > 发件人: nvo3 [mailto:[email protected]]代表 Zhou, Han > 发送时间: 2014年3月18日 11:49 > 收件人: [email protected] > 抄送: [email protected] > 主题: [nvo3] Comments to draft-quinn-vxlan-gpe-02 > > > > > Dear VXLAN-gpe Authors, > > > > VXLAN-gpe is a great extension to VXLAN, providing L3 encapsulation > > directly. However, considering the precious space in VXLAN header, it > > might be better if you could consider shrinking the size of protocol > > type field. For my understanding there is only several ethertype > values > > really required, such as IPv4/v6. Could you help rule out the > > possibilities and then shrink the field size to e.g. 8 bits or less? 8 > bits > > should be far beyond enough for this protocol type field even > > considering future extensions. But it would be so helpful for other > > extension possibilities to VXLAN. For example discussed in: > > > > http://www.ietf.org/mail-archive/web/nvo3/current/msg03388.html > > > > [Xiaohu] If you need more space in the encapsulation header, you could > exactly use a reserved bit to indicate the present of an optional > field, just like the usage of GRE Checksum Present bit. Therefore, it > seems no need for shrinking the protocol type field. > > Fix-sized header would always be the best option, which is also an advantage (may be the only advantage) of VXLAN over other new feature-rich NVO3 protocols. It would be better if we could avoid wasting header space without good reason. > > And it is likely that there will be more extension coming to VXLAN, if > > it is going to survive in the fast pace of innovation on network > > overlay. > > > > IMHO, even 0x6558, which is mentioned in section 4.2, is not required, > > because VXLAN VTEP will ignore the P bit and the protocol type anyway, > > so why not setting P bit to 0 in this situation? > > > > [Xiaohu] Thanks for pointing this out. It seems that the solution that > you desired has been described in > http://tools.ietf.org/html/draft-yong-l3vpn-nvgre-vxlan-encap-03 > > Yes, this draft stated the same as in VXLAN-gpe to use 0x6558 for ethernet and at the same time use 0x0000 for backward compatibility. So why not always using 0x0000 for ethernet? So are there only 3 values possible (0, IP, IPv6, which indicates 2 bits are enough instead of 16 bits)? > Best regards, > > Xiaohu > > --- > > Best regards, > > Han > > > > Best regards, Han _______________________________________________ nvo3 mailing list [email protected] https://www.ietf.org/mailman/listinfo/nvo3
