Samsung TV decides the Internet is broken / 2015-02-25

2015-02-25 Samsung TV decides the Internet is broken 5 years ago
Currently our Samsung 'smart' TV is convinced the Internet is broken and refuses to start any of the applications. According to some network protocol sniffing the TV decides this purely based on a DNS query for www.samsung.com which takes an interesting CNAME tour. According to what I can find this hasn't changed when the smart TV stopped working so this must be something in the software in the TV itself.
; <<>> DiG 9.4.2-P2.1 <<>> www.samsung.com a
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 39167
;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.samsung.com.               IN      A

;; ANSWER SECTION:
www.samsung.com.        253     IN      CNAME   www.samsung.com.edgekey.net.
www.samsung.com.edgekey.net. 3171 IN    CNAME   www.samsung.com.akadns.net.
www.samsung.com.akadns.net. 253 IN      CNAME   china-www.samsung.com.edgekey.net.
china-www.samsung.com.edgekey.net. 2765 IN CNAME china-www.samsung.com.edgekey.net.globalredir.akadns.net.
china-www.samsung.com.edgekey.net.globalredir.akadns.net. 853 IN CNAME e1722.g.akamaiedge.net.
e1722.g.akamaiedge.net. 14      IN      A       23.206.87.52

;; Query time: 0 msec
;; SERVER: 2001:980:14ca:42::18#53(2001:980:14ca:42::18)
;; WHEN: Wed Feb 25 20:20:34 2015
;; MSG SIZE  rcvd: 244
Online there are some similar messages: Smart TV mayhem for Sony and Samsung users after central servers go down, Internet-Ausfall bei Samsung Smart-TV

Update:
According to some reports the fix is simple: Users fix Samsung Smart TV down time themselves – Two workarounds known which both hardcode an Akamai IP for www.samsung.com and skip the CNAME chain. Remember when DNS manuals told you CNAME chains were a bad idea? They still are, I guess. I implemented the fix locally with pdns-recursor and the export-etc-hosts option which allows me to serve an A record for www.samsung.com (the IP I get from the CNAME chain). And indeed, the smart TV applications work again.

From a packet capture:
User Datagram Protocol, Src Port: 59956 (59956), Dst Port: 53 (53)
    Source port: 59956 (59956)
    Destination port: 53 (53)
    Length: 41
    Checksum: 0xcdd1 [correct]
        [Good Checksum: True]
        [Bad Checksum: False]
Domain Name System (query)
    Transaction ID: 0xf31a
    Flags: 0x0100 (Standard query)
        0... .... .... .... = Response: Message is a query
        .000 0... .... .... = Opcode: Standard query (0)
        .... ..0. .... .... = Truncated: Message is not truncated
        .... ...1 .... .... = Recursion desired: Do query recursively
        .... .... .0.. .... = Z: reserved (0)
        .... .... ...0 .... = Non-authenticated data OK: Non-authenticated data is unacceptable
    Questions: 1
    Answer RRs: 0
    Authority RRs: 0
    Additional RRs: 0
    Queries
        www.samsung.com: type A, class IN
            Name: www.samsung.com
            Type: A (Host address)
            Class: IN (0x0001)

User Datagram Protocol, Src Port: 53 (53), Dst Port: 59956 (59956)
    Source port: 53 (53)
    Destination port: 59956 (59956)
    Length: 252
    Checksum: 0x5185 [correct]
        [Good Checksum: True]
        [Bad Checksum: False]
Domain Name System (response)
    [Request In: 5]
    [Time: 0.000155000 seconds]
    Transaction ID: 0xf31a
    Flags: 0x8180 (Standard query response, No error)
        1... .... .... .... = Response: Message is a response
        .000 0... .... .... = Opcode: Standard query (0)
        .... .0.. .... .... = Authoritative: Server is not an authority for domain
        .... ..0. .... .... = Truncated: Message is not truncated
        .... ...1 .... .... = Recursion desired: Do query recursively
        .... .... 1... .... = Recursion available: Server can do recursive queries
        .... .... .0.. .... = Z: reserved (0)
        .... .... ..0. .... = Answer authenticated: Answer/authority portion was not authenticated by the server
        .... .... .... 0000 = Reply code: No error (0)
    Questions: 1
    Answer RRs: 6
    Authority RRs: 0
    Additional RRs: 0
    Queries
        www.samsung.com: type A, class IN
            Name: www.samsung.com
            Type: A (Host address)
            Class: IN (0x0001)
    Answers
        www.samsung.com: type CNAME, class IN, cname www.samsung.com.edgekey.net
            Name: www.samsung.com
            Type: CNAME (Canonical name for an alias)
            Class: IN (0x0001)
            Time to live: 1 minute, 59 seconds
            Data length: 29
            Primary name: www.samsung.com.edgekey.net
        www.samsung.com.edgekey.net: type CNAME, class IN, cname www.samsung.com.akadns.net
            Name: www.samsung.com.edgekey.net
            Type: CNAME (Canonical name for an alias)
            Class: IN (0x0001)
            Time to live: 46 minutes, 17 seconds
            Data length: 25
            Primary name: www.samsung.com.akadns.net
        www.samsung.com.akadns.net: type CNAME, class IN, cname china-www.samsung.com.edgekey.net
            Name: www.samsung.com.akadns.net
            Type: CNAME (Canonical name for an alias)
            Class: IN (0x0001)
            Time to live: 1 minute, 59 seconds
            Data length: 12
            Primary name: china-www.samsung.com.edgekey.net
        china-www.samsung.com.edgekey.net: type CNAME, class IN, cname china-www.samsung.com.edgekey.net.globalredir.akadns.net
            Name: china-www.samsung.com.edgekey.net
            Type: CNAME (Canonical name for an alias)
            Class: IN (0x0001)
            Time to live: 49 minutes, 29 seconds
            Data length: 48
            Primary name: china-www.samsung.com.edgekey.net.globalredir.akadns.net
        china-www.samsung.com.edgekey.net.globalredir.akadns.net: type CNAME, class IN, cname e1722.g.akamaiedge.net
            Name: china-www.samsung.com.edgekey.net.globalredir.akadns.net
            Type: CNAME (Canonical name for an alias)
            Class: IN (0x0001)
            Time to live: 1 minute, 17 seconds
            Data length: 21
            Primary name: e1722.g.akamaiedge.net
        e1722.g.akamaiedge.net: type A, class IN, addr 23.206.87.52
            Name: e1722.g.akamaiedge.net
            Type: A (Host address)
            Class: IN (0x0001)
            Time to live: 10 seconds
            Data length: 4
            Addr: 23.206.87.52

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