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To subscribe or unsubscribe via the World Wide Web, visit https://lists.isc.org/mailman/listinfo/dhcp-users or, via email, send a message with subject or body 'help' to dhcp-users-requ...@lists.isc.org You can reach the person managing the list at dhcp-users-ow...@lists.isc.org When replying, please edit your Subject line so it is more specific than "Re: Contents of dhcp-users digest..." Today's Topics: 1. Oversized DHCP option issues (???) ---------------------------------------------------------------------- Message: 1 Date: Sun, 23 Jan 2022 18:43:54 +0800 From: ??? <weihau.chi...@gmail.com> To: dhcp-users@lists.isc.org Subject: Oversized DHCP option issues Message-ID: <cadzkvkkfjma8ujbpfb7ghpcw_ayxbftvmvrxsu4k9wutr3e...@mail.gmail.com> Content-Type: text/plain; charset="UTF-8" Hello everyone, I'm configuring a DHCP server over a network that has multiple gateways. One of the gateways has limited bandwidth, so I'm thinking of using the classless static route defined in RFC3442 to automatically configure it. However, our routing tables are large, exceeding the DHCP 255 bytes limit. I observed that only packets within 255 bytes can be sent out successfully while exceeding the limit by a little bit will cause a malformed DHCP packet shown in Wireshark, and the DHCP server doesn't send out the option while using the whole table. In RFC3396 it specifies that the options should be concatenated when they exceeded the 255-byte limit, while I didn't find how to configure that in `dhcpd.conf`. I've tried to add multiple options that share the same DHCP code, and dhcpd just ignore the previous settings and only takes the last one. The question is, how can I send out the large table successfully? I think this problem could be practical, as the 255-byte option limit can only store 23 CIDR-255.255.255.0 table entries. -- Weihao Jiang mailto:weihau.chi...@gmail.com mailto:weihao.ji...@sjtu.edu.cn ------------------------------ Subject: Digest Footer _______________________________________________ ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information. dhcp-users mailing list dhcp-users@lists.isc.org https://lists.isc.org/mailman/listinfo/dhcp-users ------------------------------ End of dhcp-users Digest, Vol 159, Issue 2 ******************************************