Hi eksi,
Thank you upload the mib file.
Unfortunately your problem does not reproduced in my fresh installed 2.5 environment.
** To compile the HUAWAI-IPPOOL-MIB, it required also HUAWEI-MIB and IPV6-TC mibs also.
** It successfully appear the detail MIBs info.
So I guess the phenomenon belongs in your environment.
If it still reproduces even newly fresh installed box, examine to use REST/XML method as kk_sup mentioned.
Finally, please note the 2.5 version will end of support state on this month.
Thanks, Naruhiro