slice+if_range problem

[cjhust@…]

server {

listen 8888;

location / {

root html;

}

}

server {

listen 8000;

location / {

slice 128K;
proxy_set_header range $slice_range;
proxy_pass ​http://127.0.0.1:8888/;

}

}

server {

listen 8001;

location / {

proxy_pass ​http://127.0.0.1:8888/;

}

}

#curl ​http://127.0.0.1:8001/4K.mp4 -o /dev/null -v -H 'range: bytes=1-2' -H 'if-range: Wed, 09 Aug 2017 08:29:34 GMT'

• About to connect() to 127.0.0.1 port 8001 (#0)
• Trying 127.0.0.1... % Total % Received % Xferd Average Speed Time Time Time Current

Dload Upload Total Spent Left Speed

0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0* Connected to 127.0.0.1 (127.0.0.1) port 8001 (#0)

GET /4K.mp4 HTTP/1.1
User-Agent: curl/7.29.0
Host: 127.0.0.1:8001
Accept: */*
range: bytes=1-2
if-range: Wed, 09 Aug 2017 08:29:34 GMT

< HTTP/1.1 206 Partial Content
< Server: nginx/1.11.2
< Date: Tue, 15 Aug 2017 03:54:28 GMT
< Content-Type: video/mp4
< Content-Length: 2
< Connection: keep-alive
< Last-Modified: Wed, 09 Aug 2017 08:29:34 GMT
< ETag: "598ac7ee-1000"
< Content-Range: bytes 1-2/4096
<
{ [data not shown]
100 2 100 2 0 0 1010 0 --:--:-- --:--:-- --:--:-- 2000

• Connection #0 to host 127.0.0.1 left intact

return 206, meet expectation

#curl ​http://127.0.0.1:8000/4K.mp4 -o /dev/null -v -H 'range: bytes=1-2' -H 'if-range: Wed, 09 Aug 2017 08:29:34 GMT'

• About to connect() to 127.0.0.1 port 8000 (#0)
• Trying 127.0.0.1... % Total % Received % Xferd Average Speed Time Time Time Current

Dload Upload Total Spent Left Speed

0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0* Connected to 127.0.0.1 (127.0.0.1) port 8000 (#0)

GET /4K.mp4 HTTP/1.1
User-Agent: curl/7.29.0
Host: 127.0.0.1:8000
Accept: */*
range: bytes=1-2
if-range: Wed, 09 Aug 2017 08:29:34 GMT

< HTTP/1.1 200 OK
< Server: nginx/1.11.2
< Date: Tue, 15 Aug 2017 03:54:46 GMT
< Content-Type: video/mp4
< Content-Length: 4096
< Connection: keep-alive
< Last-Modified: Wed, 09 Aug 2017 08:29:34 GMT
< ETag: "598ac7ee-1000"
< Accept-Ranges: bytes
<
{ [data not shown]
100 4096 100 4096 0 0 1036k 0 --:--:-- --:--:-- --:--:-- 1333k

• Connection #0 to host 127.0.0.1 left intact

return 200, not meet expectation

Is there some reason for slice module?
for user viewport, slice and no slice method must not change the HTTP result.