It doesn't matter what books say. There is no consistency in each baby. They are all different.
6 months old is also a Growth-spurt time... and hence, they get hungrier, feed more, more often, and increase in intake is needed. Feed on-demand always... day and night. It doesn't matter that they physiologically in theory should/can sleep all night. Each baby is different. Go by your baby's cues and needs.
Both my kids were different.
I had to do different things with them both.
But, my kids, woke during the night, about every 3 hours. Sometimes less.
At 6 months old... my son also "chose" a lovey. Out of all the stuffed animals he had... he just gravitated toward this one stuffed cow... and we noticed he liked to sleep with it. That was his "lovey" since then.
My daughter on the other hand, did NOT want anything to sleep with at that age. She was more high-needs.
Then there is teething.
Then there is their developmental changes... and hitting milestones... and changes in gross motor and fine motor skills... and cognitive changes. ALL of which, affects a baby and their sleep and wakings. MANY of these things, occurs at the same time... not singly. So its not easy for baby too.
Then, when they start to roll-over, sit-up, pull-up, stand-up... these changes affects their sleep too. Because they will do it, IN the crib when they are 'supposed to' in theory, be sleeping. But, this is the way a baby "practices" these motor skills. AND... it is INvoluntary... so you can't tell them to stop, and they stop. It is instinct... they will do this.
Sleep... in a baby... is NEVER static. It always, changes. Sleep in a toddler, an older child, a pre-teen, a Teen, a College kid, an Adult, an Elderly person... always changes. It is not static nor finite. No adult now... sleeps the same way they did as a baby.
So... go by your baby's cues and needs.
There is no "template" for making a baby sleep.
"Sleeping through the night" for a baby... means... sleeping for 5-6 hour stretches. It is not by adult terms.
Then, there is if/when a baby is sick or does not feel well. They wake too.
A baby ALSO... goes through stirrings or fussying... in sleep. Or intermittent wakings... which is normal and common. Even an adult stirs at night or makes noises. I hear my Husband do that and my kids.
IF your baby is merely making noises in his sleep and is NOT fully "awake" awake.. let him be. He may re-settle himself... without your help. BUT if he is crying/hungry, then go to him. Feed him.
Know your baby's cues and needs.
If a baby needs to feed, they need to feed.
Every night... IS different.
My son at 6 months... would sometimes wake at night and need to feed. Other times, he'd be making noises/stirring at night... but he was fine and happy, then he'd go back to sleep. I didn't WAKE him... nor talk to him, nor pick him up... if he was just stirring. He was fine. I knew, he'd then go back to sleep. And I knew if it was hunger....
As a baby matures... they will naturally... get more 'able' to sleep... and self-soothe. Your baby is so young right now.
IF a baby is hungry, they are hungry. Feed him. It will NOT create a bad habit... a hungry baby cannot sleep. ESPECIALLY if going through growth-spurts. They need the extra intake.
My kids, had GINORMOUS appetites... and I breastfed them, on demand.
Also, a baby goes through "cluster-feeding" which means even feeding every single hour. It reflects, their increasing intake needs and growing.
Do what YOUR baby needs...
They do not, have static waking "schedules"... nor predictable. It always changes.... since a baby is always changing and growing and developing....
If you feed on-demand, (if you are nursing), your milk supply will increase in amounts AND in constituency, per your baby's growth and intake needs. THAT is important.
If your are Formula feeding... make sure he is getting added intake... he may need, extra ounces....
I nursed my kids on-demand for the 1at year... and after that especially at growth-spurts. Growth-spurts occurs EVERY 3 months....
all the best,
Susan