initial advertised EDNS UDP buffer size problem
bind change the initial UDP buffer size to 512(from bind 9.10.0), result in usging tcp query ROOT & GTLD Server after bind starting. as both root & gtld's edns response size greater than 512 bytes.
after bind restart, the recursion time of bind 9.10 is much longer than bind 9.9 。
reading from file g.pcap, link-type EN10MB (Ethernet)
22:17:57.543248 IP (tos 0x0, ttl 64, id 33740, offset 0, flags [none], proto UDP (17), length 67)
hk.63669 > b.root-servers.net.domain: [bad udp cksum 0x1e5a -> 0x2361!] 35054 [1au] A? google.com. ar: . OPT UDPsize=512 DO (39)
22:17:57.543297 IP (tos 0x0, ttl 64, id 33741, offset 0, flags [none], proto UDP (17), length 56)
hk.20276 > b.root-servers.net.domain: [bad udp cksum 0x1e4f -> 0x9e9b!] 28252 [1au] NS? . ar: . OPT UDPsize=512 DO (28)
22:17:57.697250 IP (tos 0x14, ttl 51, id 50860, offset 0, flags [none], proto UDP (17), length 56)
b.root-servers.net.domain > hk.20276: [udp sum ok] 28252*-| q: NS? . 0/0/1 ar: . OPT UDPsize=4096 DO (28)
22:17:57.697472 IP (tos 0x0, ttl 64, id 36179, offset 0, flags [DF], proto TCP (6), length 60)
hk.20454 > b.root-servers.net.domain: Flags [S], cksum 0x1e48 (incorrect -> 0x99e9), seq 1202528439, win 42340, options [mss 1460,sackOK,TS val 2217782756 ecr 0,nop,wscale 11], length 0
22:17:57.701445 IP (tos 0x14, ttl 51, id 50863, offset 0, flags [none], proto UDP (17), length 67)
b.root-servers.net.domain > hk.63669: [udp sum ok] 35054-| q: A? google.com. 0/0/1 ar: . OPT UDPsize=4096 DO (39)
22:17:57.701551 IP (tos 0x0, ttl 64, id 24089, offset 0, flags [DF], proto TCP (6), length 60)
hk.59642 > b.root-servers.net.domain: Flags [S], cksum 0x1e48 (incorrect -> 0x7cf5), seq 4165858289, win 42340, options [mss 1460,sackOK,TS val 2217782760 ecr 0,nop,wscale 11], length 0
22:17:57.852581 IP (tos 0x0, ttl 51, id 0, offset 0, flags [DF], proto TCP (6), length 60)
b.root-servers.net.domain > hk.20454: Flags [S.], cksum 0x63e1 (correct), seq 1881857303, ack 1202528440, win 28960, options [mss 1460,sackOK,TS val 3508620251 ecr 2217782756,nop,wscale 7], length 0
22:17:57.852634 IP (tos 0x0, ttl 64, id 36180, offset 0, flags [DF], proto TCP (6), length 52)
hk.20454 > b.root-servers.net.domain: Flags [.], cksum 0x1e40 (incorrect -> 0x031e), seq 1, ack 1, win 21, options [nop,nop,TS val 2217782911 ecr 3508620251], length 0
22:17:57.852762 IP (tos 0x0, ttl 64, id 36181, offset 0, flags [DF], proto TCP (6), length 82)
hk.20454 > b.root-servers.net.domain: Flags [P.], cksum 0x1e5e (incorrect -> 0xbc43), seq 1:31, ack 1, win 21, options [nop,nop,TS val 2217782911 ecr 3508620251], length 3045932 [1au] NS? . ar: . OPT UDPsize=4096 DO (28)
22:17:57.860436 IP (tos 0x14, ttl 51, id 0, offset 0, flags [DF], proto TCP (6), length 60)
b.root-servers.net.domain > hk.59642: Flags [S.], cksum 0x432e (correct), seq 53890507, ack 4165858290, win 28960, options [mss 1460,sackOK,TS val 3508620251 ecr 2217782760,nop,wscale 7], length 0
22:17:57.860456 IP (tos 0x0, ttl 64, id 24090, offset 0, flags [DF], proto TCP (6), length 52)
hk.59642 > b.root-servers.net.domain: Flags [.], cksum 0x1e40 (incorrect -> 0xe266), seq 1, ack 1, win 21, options [nop,nop,TS val 2217782919 ecr 3508620251], length 0
22:17:57.860527 IP (tos 0x0, ttl 64, id 24091, offset 0, flags [DF], proto TCP (6), length 93)
hk.59642 > b.root-servers.net.domain: Flags [P.], cksum 0x1e69 (incorrect -> 0x9173), seq 1:42, ack 1, win 21, options [nop,nop,TS val 2217782919 ecr 3508620251], length 415201 [1au] A? google.com. ar: . OPT UDPsize=4096 DO (39)
22:17:58.007824 IP (tos 0x0, ttl 51, id 37272, offset 0, flags [DF], proto TCP (6), length 52)
b.root-servers.net.domain > hk.20454: Flags [.], cksum 0x018b (correct), seq 1, ack 31, win 229, options [nop,nop,TS val 3508620416 ecr 2217782911], length 0
22:17:58.007994 IP (tos 0x0, ttl 51, id 37273, offset 0, flags [DF], proto TCP (6), length 1151)
b.root-servers.net.domain > hk.20454: Flags [P.], cksum 0xf32e (correct), seq 1:1100, ack 31, win 229, options [nop,nop,TS val 3508620416 ecr 2217782911], length 109945932*- q: NS? . 14/0/27 . NS f.root-servers.net., . NS l.root-servers.net., . NS j.root-servers.net., . NS d.root-servers.net., . NS m.root-servers.net., . NS i.root-servers.net., . NS e.root-servers.net., . NS c.root-servers.net., . NS g.root-servers.net., . NS b.root-servers.net., . NS h.root-servers.net., . NS a.root-servers.net., . NS k.root-servers.net., . RRSIG ar: a.root-servers.net. A 198.41.0.4, b.root-servers.net. A 199.9.14.201, c.root-servers.net. A 192.33.4.12, d.root-servers.net. A 199.7.91.13, e.root-servers.net. A 192.203.230.10, f.root-servers.net. A 192.5.5.241, g.root-servers.net. A 192.112.36.4, h.root-servers.net. A 198.97.190.53, i.root-servers.net. A 192.36.148.17, j.root-servers.net. A 192.58.128.30, k.root-servers.net. A 193.0.14.129, l.root-servers.net. A 199.7.83.42, m.root-servers.net. A 202.12.27.33, a.root-servers.net. AAAA 2001:503:ba3e::2:30, b.root-servers.net. AAAA 2001:500:200::b, c.root-servers.net. AAAA 2001:500:2::c, d.root-servers.net. AAAA 2001:500:2d::d, e.root-servers.net. AAAA 2001:500:a8::e, f.root-servers.net. AAAA 2001:500:2f::f, g.root-servers.net. AAAA 2001:500:12::d0d, h.root-servers.net. AAAA 2001:500:1::53, i.root-servers.net. AAAA 2001:7fe::53, j.root-servers.net. AAAA 2001:503:c27::2:30, k.root-servers.net. AAAA 2001:7fd::1, l.root-servers.net. AAAA 2001:500:9f::42, m.root-servers.net. AAAA 2001:dc3::35, . OPT UDPsize=4096 DO (1097)
22:17:58.008018 IP (tos 0x0, ttl 64, id 36182, offset 0, flags [DF], proto TCP (6), length 52)
hk.20454 > b.root-servers.net.domain: Flags [.], cksum 0x1e40 (incorrect -> 0xfd72), seq 31, ack 1100, win 23, options [nop,nop,TS val 2217783066 ecr 3508620416], length 0
22:17:58.008573 IP (tos 0x0, ttl 64, id 36183, offset 0, flags [DF], proto TCP (6), length 52)
hk.20454 > b.root-servers.net.domain: Flags [F.], cksum 0x1e40 (incorrect -> 0xfd70), seq 31, ack 1100, win 23, options [nop,nop,TS val 2217783067 ecr 3508620416], length 0
22:17:58.019490 IP (tos 0x14, ttl 51, id 325, offset 0, flags [DF], proto TCP (6), length 52)
b.root-servers.net.domain > hk.59642: Flags [.], cksum 0xe0bf (correct), seq 1, ack 42, win 229, options [nop,nop,TS val 3508620425 ecr 2217782919], length 0
22:17:58.019657 IP (tos 0x14, ttl 51, id 326, offset 0, flags [DF], proto TCP (6), length 1224)
b.root-servers.net.domain > hk.59642: Flags [P.], cksum 0x4548 (correct), seq 1:1173, ack 42, win 229, options [nop,nop,TS val 3508620425 ecr 2217782919], length 11725201- q: A? google.com. 0/15/27 ns: com. NS h.gtld-servers.net., com. NS m.gtld-servers.net., com. NS l.gtld-servers.net., com. NS j.gtld-servers.net., com. NS i.gtld-servers.net., com. NS g.gtld-servers.net., com. NS f.gtld-servers.net., com. NS b.gtld-servers.net., com. NS a.gtld-servers.net., com. NS c.gtld-servers.net., com. NS e.gtld-servers.net., com. NS k.gtld-servers.net., com. NS d.gtld-servers.net., com. DS, com. RRSIG ar: a.gtld-servers.net. A 192.5.6.30, b.gtld-servers.net. A 192.33.14.30, c.gtld-servers.net. A 192.26.92.30, d.gtld-servers.net. A 192.31.80.30, e.gtld-servers.net. A 192.12.94.30, f.gtld-servers.net. A 192.35.51.30, g.gtld-servers.net. A 192.42.93.30, h.gtld-servers.net. A 192.54.112.30, i.gtld-servers.net. A 192.43.172.30, j.gtld-servers.net. A 192.48.79.30, k.gtld-servers.net. A 192.52.178.30, l.gtld-servers.net. A 192.41.162.30, m.gtld-servers.net. A 192.55.83.30, a.gtld-servers.net. AAAA 2001:503:a83e::2:30, b.gtld-servers.net. AAAA 2001:503:231d::2:30, c.gtld-servers.net. AAAA 2001:503:83eb::30, d.gtld-servers.net. AAAA 2001:500:856e::30, e.gtld-servers.net. AAAA 2001:502:1ca1::30, f.gtld-servers.net. AAAA 2001:503:d414::30, g.gtld-servers.net. AAAA 2001:503:eea3::30, h.gtld-servers.net. AAAA 2001:502:8cc::30, i.gtld-servers.net. AAAA 2001:503:39c1::30, j.gtld-servers.net. AAAA 2001:502:7094::30, k.gtld-servers.net. AAAA 2001:503:d2d::30, l.gtld-servers.net. AAAA 2001:500:d937::30, m.gtld-servers.net. AAAA 2001:501:b1f9::30, . OPT UDPsize=4096 DO (1170)
22:17:58.019670 IP (tos 0x0, ttl 64, id 24092, offset 0, flags [DF], proto TCP (6), length 52)
hk.59642 > b.root-servers.net.domain: Flags [.], cksum 0x1e40 (incorrect -> 0xdc5a), seq 42, ack 1173, win 23, options [nop,nop,TS val 2217783078 ecr 3508620425], length 0
22:17:58.020000 IP (tos 0x0, ttl 64, id 43314, offset 0, flags [none], proto UDP (17), length 67)
hk.15653 > j.gtld-servers.net.domain: [bad udp cksum 0x57d6 -> 0x3e39!] 61482 [1au] A? google.com. ar: . OPT UDPsize=512 DO (39)
22:17:58.020038 IP (tos 0x0, ttl 64, id 24093, offset 0, flags [DF], proto TCP (6), length 52)
hk.59642 > b.root-servers.net.domain: Flags [F.], cksum 0x1e40 (incorrect -> 0xdc59), seq 42, ack 1173, win 23, options [nop,nop,TS val 2217783078 ecr 3508620425], length 0
22:17:58.163676 IP (tos 0x0, ttl 51, id 37274, offset 0, flags [DF], proto TCP (6), length 52)
b.root-servers.net.domain > hk.20454: Flags [F.], cksum 0xfc05 (correct), seq 1100, ack 32, win 229, options [nop,nop,TS val 3508620572 ecr 2217783067], length 0
22:17:58.163726 IP (tos 0x0, ttl 64, id 36184, offset 0, flags [DF], proto TCP (6), length 52)
hk.20454 > b.root-servers.net.domain: Flags [.], cksum 0x1e40 (incorrect -> 0xfc38), seq 32, ack 1101, win 23, options [nop,nop,TS val 2217783222 ecr 3508620572], length 0
22:17:58.175412 IP (tos 0x14, ttl 54, id 43332, offset 0, flags [none], proto UDP (17), length 533)
j.gtld-servers.net.domain > hk.15653: [udp sum ok] 61482-| q: A? google.com. 0/7/4 ns: google.com. NS ns2.google.com., google.com. NS ns1.google.com., google.com. NS ns3.google.com., google.com. NS ns4.google.com., CK0POJMG874LJREF7EFN8430QVIT8BSM.com. Type50, CK0POJMG874LJREF7EFN8430QVIT8BSM.com. RRSIG, S848U70KJDCTE8UH1N07QH2EK7LNOUC6.com. Type50 ar: ns2.google.com. AAAA 2001:4860:4802:34::a, ns2.google.com. A 216.239.34.10, ns1.google.com. AAAA 2001:4860:4802:32::a, . OPT UDPsize=4096 DO (505)
22:17:58.175647 IP (tos 0x0, ttl 64, id 30331, offset 0, flags [DF], proto TCP (6), length 60)
hk.41221 > j.gtld-servers.net.domain: Flags [S], cksum 0x57c4 (incorrect -> 0x6dbe), seq 777836985, win 42340, options [mss 1460,sackOK,TS val 2217783234 ecr 0,nop,wscale 11], length 0
22:17:58.178918 IP (tos 0x14, ttl 51, id 327, offset 0, flags [DF], proto TCP (6), length 52)
b.root-servers.net.domain > hk.59642: Flags [F.], cksum 0xdaeb (correct), seq 1173, ack 43, win 229, options [nop,nop,TS val 3508620584 ecr 2217783078], length 0
22:17:58.178939 IP (tos 0x0, ttl 64, id 24094, offset 0, flags [DF], proto TCP (6), length 52)
hk.59642 > b.root-servers.net.domain: Flags [.], cksum 0x1e40 (incorrect -> 0xdb1a), seq 43, ack 1174, win 23, options [nop,nop,TS val 2217783237 ecr 3508620584], length 0
22:17:58.332020 IP (tos 0x0, ttl 54, id 49700, offset 0, flags [none], proto TCP (6), length 44)
j.gtld-servers.net.domain > hk.41221: Flags [S.], cksum 0x3f2c (correct), seq 3326577671, ack 777836986, win 1460, options [mss 1460], length 0
22:17:58.332154 IP (tos 0x0, ttl 64, id 30332, offset 0, flags [DF], proto TCP (6), length 40)
hk.41221 > j.gtld-servers.net.domain: Flags [.], cksum 0x57b0 (incorrect -> 0xb738), seq 1, ack 1, win 42340, length 0
22:17:58.332320 IP (tos 0x0, ttl 64, id 30333, offset 0, flags [DF], proto TCP (6), length 81)
hk.41221 > j.gtld-servers.net.domain: Flags [P.], cksum 0x57d9 (incorrect -> 0x20e9), seq 1:42, ack 1, win 42340, length 4122957 [1au] A? google.com. ar: . OPT UDPsize=4096 DO (39)
22:17:58.488944 IP (tos 0x0, ttl 54, id 57511, offset 0, flags [DF], proto TCP (6), length 814)
j.gtld-servers.net.domain > hk.41221: Flags [P.], cksum 0xab7f (correct), seq 1:775, ack 42, win 65535, length 77422957- q: A? google.com. 0/8/9 ns: google.com. NS ns2.google.com., google.com. NS ns1.google.com., google.com. NS ns3.google.com., google.com. NS ns4.google.com., CK0POJMG874LJREF7EFN8430QVIT8BSM.com. Type50, CK0POJMG874LJREF7EFN8430QVIT8BSM.com. RRSIG, S848U70KJDCTE8UH1N07QH2EK7LNOUC6.com. Type50, S848U70KJDCTE8UH1N07QH2EK7LNOUC6.com. RRSIG ar: ns2.google.com. AAAA 2001:4860:4802:34::a, ns2.google.com. A 216.239.34.10, ns1.google.com. AAAA 2001:4860:4802:32::a, ns1.google.com. A 216.239.32.10, ns3.google.com. AAAA 2001:4860:4802:36::a, ns3.google.com. A 216.239.36.10, ns4.google.com. AAAA 2001:4860:4802:38::a, ns4.google.com. A 216.239.38.10, . OPT UDPsize=4096 DO (772)
22:17:58.488994 IP (tos 0x0, ttl 64, id 30334, offset 0, flags [DF], proto TCP (6), length 40)
hk.41221 > j.gtld-servers.net.domain: Flags [.], cksum 0x57b0 (incorrect -> 0xb01d), seq 42, ack 775, win 43344, length 0
22:17:58.489383 IP (tos 0x0, ttl 64, id 9006, offset 0, flags [none], proto UDP (17), length 67)
hk.41589 > ns4.google.com.domain: [bad udp cksum 0x4781 -> 0x1bcb!] 48541 [1au] A? google.com. ar: . OPT UDPsize=512 DO (39)
22:17:58.489427 IP (tos 0x0, ttl 64, id 30335, offset 0, flags [DF], proto TCP (6), length 40)
hk.41221 > j.gtld-servers.net.domain: Flags [F.], cksum 0x57b0 (incorrect -> 0xb01c), seq 42, ack 775, win 43344, length 0
22:17:58.645265 IP (tos 0x0, ttl 54, id 57520, offset 0, flags [DF], proto TCP (6), length 40)
j.gtld-servers.net.domain > hk.41221: Flags [.], cksum 0x596d (correct), seq 775, ack 43, win 65535, length 0
22:17:58.645269 IP (tos 0x0, ttl 54, id 57521, offset 0, flags [DF], proto TCP (6), length 40)
j.gtld-servers.net.domain > hk.41221: Flags [F.], cksum 0x596c (correct), seq 775, ack 43, win 65535, length 0
22:17:58.645328 IP (tos 0x0, ttl 64, id 56815, offset 0, flags [DF], proto TCP (6), length 40)
hk.41221 > j.gtld-servers.net.domain: Flags [.], cksum 0xb01b (correct), seq 43, ack 776, win 43344, length 0
22:17:58.654219 IP (tos 0x0, ttl 44, id 2814, offset 0, flags [none], proto UDP (17), length 72)
ns4.google.com.domain > hk.41589: [udp sum ok] 48541*- q: A? google.com. 1/0/0 google.com. A 172.217.24.14 (44)
[root@hk ~]#