DNS resolution, Browser navigation, and cache

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP

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7
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I know NS update could take over 24h. However during this process there is something that intrigues me.

I can’t change ISP router’s DNS so I set WAN/LAN to use Google Public DNS

The process scenario:

  1. I change a domain NS
  2. After some minutes, I go to dnschecker.org , I add a custom DNS Server to enter Google public nameservers
  3. dnschecker.org let’s say it lists 50% of DNS updated servers including Google DNS
  4. I go to windows command line and enter ipconfing /flushdns
  5. I clear all chrome file cache (Ctrl+Shift+Del), clear chrome host (chrome://net-internals/#dns) cache and flush chrome sockets pool ( chrome://net-internals/#sockets )
  6. Finnaly I open the website in new Chrome (or other browser) window tab, and the displayed website is the old one. However, at the same time, if I access the domain through some free online proxy like Whoer, the website loads the updated DNS version.
  7. Only 24 hours later my chrome loads the updated DNS site version.

How could that be? Am I missing something?

share|improve this question

    up vote
    7
    down vote

    favorite

    4

    I know NS update could take over 24h. However during this process there is something that intrigues me.

    I can’t change ISP router’s DNS so I set WAN/LAN to use Google Public DNS

    The process scenario:

    1. I change a domain NS
    2. After some minutes, I go to dnschecker.org , I add a custom DNS Server to enter Google public nameservers
    3. dnschecker.org let’s say it lists 50% of DNS updated servers including Google DNS
    4. I go to windows command line and enter ipconfing /flushdns
    5. I clear all chrome file cache (Ctrl+Shift+Del), clear chrome host (chrome://net-internals/#dns) cache and flush chrome sockets pool ( chrome://net-internals/#sockets )
    6. Finnaly I open the website in new Chrome (or other browser) window tab, and the displayed website is the old one. However, at the same time, if I access the domain through some free online proxy like Whoer, the website loads the updated DNS version.
    7. Only 24 hours later my chrome loads the updated DNS site version.

    How could that be? Am I missing something?

    share|improve this question

      up vote
      7
      down vote

      favorite

      4

      up vote
      7
      down vote

      favorite

      4
      4

      I know NS update could take over 24h. However during this process there is something that intrigues me.

      I can’t change ISP router’s DNS so I set WAN/LAN to use Google Public DNS

      The process scenario:

      1. I change a domain NS
      2. After some minutes, I go to dnschecker.org , I add a custom DNS Server to enter Google public nameservers
      3. dnschecker.org let’s say it lists 50% of DNS updated servers including Google DNS
      4. I go to windows command line and enter ipconfing /flushdns
      5. I clear all chrome file cache (Ctrl+Shift+Del), clear chrome host (chrome://net-internals/#dns) cache and flush chrome sockets pool ( chrome://net-internals/#sockets )
      6. Finnaly I open the website in new Chrome (or other browser) window tab, and the displayed website is the old one. However, at the same time, if I access the domain through some free online proxy like Whoer, the website loads the updated DNS version.
      7. Only 24 hours later my chrome loads the updated DNS site version.

      How could that be? Am I missing something?

      share|improve this question

      I know NS update could take over 24h. However during this process there is something that intrigues me.

      I can’t change ISP router’s DNS so I set WAN/LAN to use Google Public DNS

      The process scenario:

      1. I change a domain NS
      2. After some minutes, I go to dnschecker.org , I add a custom DNS Server to enter Google public nameservers
      3. dnschecker.org let’s say it lists 50% of DNS updated servers including Google DNS
      4. I go to windows command line and enter ipconfing /flushdns
      5. I clear all chrome file cache (Ctrl+Shift+Del), clear chrome host (chrome://net-internals/#dns) cache and flush chrome sockets pool ( chrome://net-internals/#sockets )
      6. Finnaly I open the website in new Chrome (or other browser) window tab, and the displayed website is the old one. However, at the same time, if I access the domain through some free online proxy like Whoer, the website loads the updated DNS version.
      7. Only 24 hours later my chrome loads the updated DNS site version.

      How could that be? Am I missing something?

      dns browser-cache wan ipconfig

      share|improve this question

      share|improve this question

      share|improve this question

      share|improve this question

      edited Nov 29 at 12:53

      Dave M

      12.7k92838

      12.7k92838

      asked Nov 29 at 12:47

      André A.

      362

      362

          2 Answers
          2

          active

          oldest

          votes

          up vote
          10
          down vote

          The DNS server of your ISP has your address in its cache, and so is returning
          the old address. It will keep on doing so, until the
          Time To Live (TTL)
          of your data will expire.

          DNS records are stored in cache, mainly to improve performance of DNS queries.
          Every DNS record has a Time to Live (TTL) value, which is the time DNS servers
          should store that record in cache. Even if a record is changed, DNS servers
          will continue working with its former value from the cache until this time has passed.

          DNS propagation is the time required for DNS servers worldwide
          to update their cached information for a domain name.
          It is influenced by the TTL of DNS records that might have changed,
          but there are also other factors that could come into play.

          A DNS change may require up to 72 hours to propagate worldwide,
          although most often this happens in a matter of hours.

          To speed up the propagation time is possible by having your TTL set to a
          lower number (not recommended), for example 14400 (4 hours).
          But you should do that well before the NS change, maybe as much as
          96 hours in advance.

          When you query a DNS server that does not have your DNS in its cache,
          you might find that it returns the new DNS record, if the change
          has already propagated that far.

          share|improve this answer

          • 1

            @PimpJuiceIT: You’re a Jolly Good Fellow.
            – harrymc
            Nov 30 at 19:49

          up vote
          3
          down vote

          As you noted, you are using your ISP’s router, and it appears to be set to use only the ISP’s DNS servers.

          Meanwhile, you’ve used the website to check Google’s DNS servers. You could infact do this on your local machine too – nslookup <domain> 8.8.8.8 in a command prompt will query 8.8.8.8 for the IP of <domain>.

          What you’re seeing is that most DNS servers on the ‘web’ have updated, yet your ISP’s DNS server is still returning the OLD result, and will continue to do so until it updates. You can bypass this issue by simply not using your ISP’s DNS servers, setting them manually on your machine (however, this will work only if your ISP isn’t blocking external DNS access).

          Once your ISP’s DNS servers updated, you then receive the updated page, just like everyone else on the web will.

          share|improve this answer

          • 1

            If the ISP is blocking external access, using nslookup example.com 8.8.8.8 will be blocked too.
            – ivanivan
            Nov 30 at 2:40

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          2 Answers
          2

          active

          oldest

          votes

          2 Answers
          2

          active

          oldest

          votes

          active

          oldest

          votes

          active

          oldest

          votes

          up vote
          10
          down vote

          The DNS server of your ISP has your address in its cache, and so is returning
          the old address. It will keep on doing so, until the
          Time To Live (TTL)
          of your data will expire.

          DNS records are stored in cache, mainly to improve performance of DNS queries.
          Every DNS record has a Time to Live (TTL) value, which is the time DNS servers
          should store that record in cache. Even if a record is changed, DNS servers
          will continue working with its former value from the cache until this time has passed.

          DNS propagation is the time required for DNS servers worldwide
          to update their cached information for a domain name.
          It is influenced by the TTL of DNS records that might have changed,
          but there are also other factors that could come into play.

          A DNS change may require up to 72 hours to propagate worldwide,
          although most often this happens in a matter of hours.

          To speed up the propagation time is possible by having your TTL set to a
          lower number (not recommended), for example 14400 (4 hours).
          But you should do that well before the NS change, maybe as much as
          96 hours in advance.

          When you query a DNS server that does not have your DNS in its cache,
          you might find that it returns the new DNS record, if the change
          has already propagated that far.

          share|improve this answer

          • 1

            @PimpJuiceIT: You’re a Jolly Good Fellow.
            – harrymc
            Nov 30 at 19:49

          up vote
          10
          down vote

          The DNS server of your ISP has your address in its cache, and so is returning
          the old address. It will keep on doing so, until the
          Time To Live (TTL)
          of your data will expire.

          DNS records are stored in cache, mainly to improve performance of DNS queries.
          Every DNS record has a Time to Live (TTL) value, which is the time DNS servers
          should store that record in cache. Even if a record is changed, DNS servers
          will continue working with its former value from the cache until this time has passed.

          DNS propagation is the time required for DNS servers worldwide
          to update their cached information for a domain name.
          It is influenced by the TTL of DNS records that might have changed,
          but there are also other factors that could come into play.

          A DNS change may require up to 72 hours to propagate worldwide,
          although most often this happens in a matter of hours.

          To speed up the propagation time is possible by having your TTL set to a
          lower number (not recommended), for example 14400 (4 hours).
          But you should do that well before the NS change, maybe as much as
          96 hours in advance.

          When you query a DNS server that does not have your DNS in its cache,
          you might find that it returns the new DNS record, if the change
          has already propagated that far.

          share|improve this answer

          • 1

            @PimpJuiceIT: You’re a Jolly Good Fellow.
            – harrymc
            Nov 30 at 19:49

          up vote
          10
          down vote

          up vote
          10
          down vote

          The DNS server of your ISP has your address in its cache, and so is returning
          the old address. It will keep on doing so, until the
          Time To Live (TTL)
          of your data will expire.

          DNS records are stored in cache, mainly to improve performance of DNS queries.
          Every DNS record has a Time to Live (TTL) value, which is the time DNS servers
          should store that record in cache. Even if a record is changed, DNS servers
          will continue working with its former value from the cache until this time has passed.

          DNS propagation is the time required for DNS servers worldwide
          to update their cached information for a domain name.
          It is influenced by the TTL of DNS records that might have changed,
          but there are also other factors that could come into play.

          A DNS change may require up to 72 hours to propagate worldwide,
          although most often this happens in a matter of hours.

          To speed up the propagation time is possible by having your TTL set to a
          lower number (not recommended), for example 14400 (4 hours).
          But you should do that well before the NS change, maybe as much as
          96 hours in advance.

          When you query a DNS server that does not have your DNS in its cache,
          you might find that it returns the new DNS record, if the change
          has already propagated that far.

          share|improve this answer

          The DNS server of your ISP has your address in its cache, and so is returning
          the old address. It will keep on doing so, until the
          Time To Live (TTL)
          of your data will expire.

          DNS records are stored in cache, mainly to improve performance of DNS queries.
          Every DNS record has a Time to Live (TTL) value, which is the time DNS servers
          should store that record in cache. Even if a record is changed, DNS servers
          will continue working with its former value from the cache until this time has passed.

          DNS propagation is the time required for DNS servers worldwide
          to update their cached information for a domain name.
          It is influenced by the TTL of DNS records that might have changed,
          but there are also other factors that could come into play.

          A DNS change may require up to 72 hours to propagate worldwide,
          although most often this happens in a matter of hours.

          To speed up the propagation time is possible by having your TTL set to a
          lower number (not recommended), for example 14400 (4 hours).
          But you should do that well before the NS change, maybe as much as
          96 hours in advance.

          When you query a DNS server that does not have your DNS in its cache,
          you might find that it returns the new DNS record, if the change
          has already propagated that far.

          share|improve this answer

          share|improve this answer

          share|improve this answer

          edited Nov 30 at 8:07

          answered Nov 29 at 13:17

          harrymc

          250k10258554

          250k10258554

          • 1

            @PimpJuiceIT: You’re a Jolly Good Fellow.
            – harrymc
            Nov 30 at 19:49

          • 1

            @PimpJuiceIT: You’re a Jolly Good Fellow.
            – harrymc
            Nov 30 at 19:49

          1

          1

          @PimpJuiceIT: You’re a Jolly Good Fellow.
          – harrymc
          Nov 30 at 19:49

          @PimpJuiceIT: You’re a Jolly Good Fellow.
          – harrymc
          Nov 30 at 19:49

          up vote
          3
          down vote

          As you noted, you are using your ISP’s router, and it appears to be set to use only the ISP’s DNS servers.

          Meanwhile, you’ve used the website to check Google’s DNS servers. You could infact do this on your local machine too – nslookup <domain> 8.8.8.8 in a command prompt will query 8.8.8.8 for the IP of <domain>.

          What you’re seeing is that most DNS servers on the ‘web’ have updated, yet your ISP’s DNS server is still returning the OLD result, and will continue to do so until it updates. You can bypass this issue by simply not using your ISP’s DNS servers, setting them manually on your machine (however, this will work only if your ISP isn’t blocking external DNS access).

          Once your ISP’s DNS servers updated, you then receive the updated page, just like everyone else on the web will.

          share|improve this answer

          • 1

            If the ISP is blocking external access, using nslookup example.com 8.8.8.8 will be blocked too.
            – ivanivan
            Nov 30 at 2:40

          up vote
          3
          down vote

          As you noted, you are using your ISP’s router, and it appears to be set to use only the ISP’s DNS servers.

          Meanwhile, you’ve used the website to check Google’s DNS servers. You could infact do this on your local machine too – nslookup <domain> 8.8.8.8 in a command prompt will query 8.8.8.8 for the IP of <domain>.

          What you’re seeing is that most DNS servers on the ‘web’ have updated, yet your ISP’s DNS server is still returning the OLD result, and will continue to do so until it updates. You can bypass this issue by simply not using your ISP’s DNS servers, setting them manually on your machine (however, this will work only if your ISP isn’t blocking external DNS access).

          Once your ISP’s DNS servers updated, you then receive the updated page, just like everyone else on the web will.

          share|improve this answer

          • 1

            If the ISP is blocking external access, using nslookup example.com 8.8.8.8 will be blocked too.
            – ivanivan
            Nov 30 at 2:40

          up vote
          3
          down vote

          up vote
          3
          down vote

          As you noted, you are using your ISP’s router, and it appears to be set to use only the ISP’s DNS servers.

          Meanwhile, you’ve used the website to check Google’s DNS servers. You could infact do this on your local machine too – nslookup <domain> 8.8.8.8 in a command prompt will query 8.8.8.8 for the IP of <domain>.

          What you’re seeing is that most DNS servers on the ‘web’ have updated, yet your ISP’s DNS server is still returning the OLD result, and will continue to do so until it updates. You can bypass this issue by simply not using your ISP’s DNS servers, setting them manually on your machine (however, this will work only if your ISP isn’t blocking external DNS access).

          Once your ISP’s DNS servers updated, you then receive the updated page, just like everyone else on the web will.

          share|improve this answer

          As you noted, you are using your ISP’s router, and it appears to be set to use only the ISP’s DNS servers.

          Meanwhile, you’ve used the website to check Google’s DNS servers. You could infact do this on your local machine too – nslookup <domain> 8.8.8.8 in a command prompt will query 8.8.8.8 for the IP of <domain>.

          What you’re seeing is that most DNS servers on the ‘web’ have updated, yet your ISP’s DNS server is still returning the OLD result, and will continue to do so until it updates. You can bypass this issue by simply not using your ISP’s DNS servers, setting them manually on your machine (however, this will work only if your ISP isn’t blocking external DNS access).

          Once your ISP’s DNS servers updated, you then receive the updated page, just like everyone else on the web will.

          share|improve this answer

          share|improve this answer

          share|improve this answer

          edited Nov 30 at 4:03

          Scott

          15.5k113789

          15.5k113789

          answered Nov 29 at 13:05

          djsmiley2k

          4,86612335

          4,86612335

          • 1

            If the ISP is blocking external access, using nslookup example.com 8.8.8.8 will be blocked too.
            – ivanivan
            Nov 30 at 2:40

          • 1

            If the ISP is blocking external access, using nslookup example.com 8.8.8.8 will be blocked too.
            – ivanivan
            Nov 30 at 2:40

          1

          1

          If the ISP is blocking external access, using nslookup example.com 8.8.8.8 will be blocked too.
          – ivanivan
          Nov 30 at 2:40

          If the ISP is blocking external access, using nslookup example.com 8.8.8.8 will be blocked too.
          – ivanivan
          Nov 30 at 2:40

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